More explicitly differentiate between iterator helper methods/objects (…

…mdn#36711)

* More explicitly differentiate between iterator helper methods/objects

* Update files/en-us/web/javascript/reference/global_objects/iterator/index.md

files/en-us/mozilla/firefox/releases/131/index.md

@@ -16,7 +16,7 @@ This article provides information about the changes in Firefox 131 that affect d
 
 ### JavaScript
 
-- Support for synchronous iterator helpers has been added, including: {{jsxref("Iterator.prototype.drop()")}}, {{jsxref("Iterator.prototype.every()")}}, {{jsxref("Iterator.prototype.filter()")}}, {{jsxref("Iterator.prototype.find()")}}, {{jsxref("Iterator.prototype.flatMap()")}}, {{jsxref("Iterator.prototype.forEach()")}}, {{jsxref("Iterator.prototype.map()")}}, {{jsxref("Iterator.prototype.reduce()")}}, {{jsxref("Iterator.prototype.some()")}}, and {{jsxref("Iterator.prototype.take()")}}. These helpers allow `Array`-like operations on iterators without having to create intermediate `Array` objects. They can also be used with very large data sets where creating an intermediate `Array` would not even be possible. For more information, see [Iterator helpers](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) in the `Iterator` interface. ([Firefox bug 1896390](https://bugzil.la/1896390)).
+- Support for synchronous iterator helper methods has been added, including: {{jsxref("Iterator.prototype.drop()")}}, {{jsxref("Iterator.prototype.every()")}}, {{jsxref("Iterator.prototype.filter()")}}, {{jsxref("Iterator.prototype.find()")}}, {{jsxref("Iterator.prototype.flatMap()")}}, {{jsxref("Iterator.prototype.forEach()")}}, {{jsxref("Iterator.prototype.map()")}}, {{jsxref("Iterator.prototype.reduce()")}}, {{jsxref("Iterator.prototype.some()")}}, and {{jsxref("Iterator.prototype.take()")}}. These helpers allow `Array`-like operations on iterators without having to create intermediate `Array` objects. They can also be used with very large data sets where creating an intermediate `Array` would not even be possible. For more information, see [Iterator helper methods](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_methods) in the `Iterator` interface. ([Firefox bug 1896390](https://bugzil.la/1896390)).
 
 ### HTTP
 

files/en-us/web/javascript/reference/global_objects/iterator/drop/index.md

@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Iterator.drop
 
 {{JSRef}}
 
-The **`drop()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) that skips the given number of elements at the start of this iterator.
+The **`drop()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects) that skips the given number of elements at the start of this iterator.
 
 ## Syntax
 
@@ -22,7 +22,7 @@ drop(limit)
 
 ### Return value
 
-A new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers). The first time the returned iterator helper's `next()` method is called, the current iterator is immediately advanced by `limit` elements, and then the next element (the `limit+1`-th element) is yielded. The iterator helper then yields the remaining elements one-by-one. If the current iterator has fewer than `limit` elements, the new iterator helper will be immediately completed the first time `next()` is called.
+A new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects). The first time the returned iterator helper's `next()` method is called, the current iterator is immediately advanced by `limit` elements, and then the next element (the `limit+1`-th element) is yielded. The iterator helper then yields the remaining elements one-by-one. If the current iterator has fewer than `limit` elements, the new iterator helper will be immediately completed the first time `next()` is called.
 
 ### Exceptions
 

files/en-us/web/javascript/reference/global_objects/iterator/filter/index.md

@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Iterator.filter
 
 {{JSRef}}
 
-The **`filter()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) that yields only those elements of the iterator for which the provided callback function returns `true`.
+The **`filter()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects) that yields only those elements of the iterator for which the provided callback function returns `true`.
 
 ## Syntax
 
@@ -26,7 +26,7 @@ filter(callbackFn)
 
 ### Return value
 
-A new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers). Each time the iterator helper's `next()` method is called, it returns the next element in the iterator for which the callback function returns `true`. When the underlying iterator is completed, the iterator helper is also completed (the `next()` method produces `{ value: undefined, done: true }`).
+A new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects). Each time the iterator helper's `next()` method is called, it returns the next element in the iterator for which the callback function returns `true`. When the underlying iterator is completed, the iterator helper object is also completed (the `next()` method produces `{ value: undefined, done: true }`).
 
 ## Description
 

files/en-us/web/javascript/reference/global_objects/iterator/flatmap/index.md

@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Iterator.flatMap
 
 {{JSRef}}
 
-The **`flatMap()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) that takes each element in the original iterator, runs it through a mapping function, and yields elements returned by the mapping function (which are contained in another iterator or iterable).
+The **`flatMap()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects) that takes each element in the original iterator, runs it through a mapping function, and yields elements returned by the mapping function (which are contained in another iterator or iterable).
 
 ## Syntax
 
@@ -26,7 +26,7 @@ flatMap(callbackFn)
 
 ### Return value
 
-A new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers). The first time the iterator helper's `next()` method is called, it calls `callbackFn` on the first element produced by the underlying iterator, and the return value, which should be an iterator or iterable, is yielded one-by-one by the iterator helper (like {{jsxref("Operators/yield*", "yield*")}}). The next element is fetched from the underlying iterator when the previous one returned by `callbackFn` is completed. When the underlying iterator is completed, the iterator helper is also completed (the `next()` method produces `{ value: undefined, done: true }`).
+A new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects). The first time the iterator helper's `next()` method is called, it calls `callbackFn` on the first element produced by the underlying iterator, and the return value, which should be an iterator or iterable, is yielded one-by-one by the iterator helper (like {{jsxref("Operators/yield*", "yield*")}}). The next element is fetched from the underlying iterator when the previous one returned by `callbackFn` is completed. When the underlying iterator is completed, the iterator helper is also completed (the `next()` method produces `{ value: undefined, done: true }`).
 
 ### Exceptions
 

files/en-us/web/javascript/reference/global_objects/iterator/index.md

@@ -34,7 +34,7 @@ Each of these iterators have a distinct prototype object, which defines the `nex
 
 All of these prototype objects inherit from `Iterator.prototype`, which provides a [`[Symbol.iterator]()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/iterator) method that returns the iterator object itself, making the iterator also [iterable](/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#the_iterable_protocol).
 
-### Iterator helpers
+### Iterator helper methods
 
 > [!NOTE]
 > These methods are _iterator_ helpers, not _iterable_ helpers, because the only requirement for an object to be iterable is just the presence of a `[Symbol.iterator]()` method. There is no shared prototype to install these methods on.
@@ -90,7 +90,11 @@ You will find many iterator methods analogous to array methods, such as:
 
 {{jsxref("Iterator.prototype.drop()")}} and {{jsxref("Iterator.prototype.take()")}} combined are somewhat analogous to {{jsxref("Array.prototype.slice()")}}.
 
-Among these methods, {{jsxref("Iterator/filter", "filter()")}}, {{jsxref("Iterator/flatMap", "flatMap()")}}, {{jsxref("Iterator/map", "map()")}}, {{jsxref("Iterator/drop", "drop()")}}, and {{jsxref("Iterator/take", "take()")}} return a new _Iterator Helper_ object. The iterator helper is also an `Iterator` instance, making the helper methods chainable. All iterator helper objects inherit from a common prototype object, which implements the iterator protocol:
+### Iterator helper objects
+
+> **Note:** _Iterator helper objects_ and _iterator helper methods_ are two different concepts. An Iterator helper object is detectable at runtime, while "iterator helper method" is just a name for a set of methods for comprehension. _Iterator helper_ may refer to either the object or the method, depending on the context.
+
+Among the iterator helper methods, {{jsxref("Iterator/filter", "filter()")}}, {{jsxref("Iterator/flatMap", "flatMap()")}}, {{jsxref("Iterator/map", "map()")}}, {{jsxref("Iterator/drop", "drop()")}}, and {{jsxref("Iterator/take", "take()")}} return a new _Iterator Helper_ object. The iterator helper is also an `Iterator` instance, making these helper methods chainable. All iterator helper objects inherit from a common prototype object, which implements the iterator protocol:
 
 - `next()`
   - : Calls the `next()` method of the underlying iterator, applies the helper method to the result, and returns the result.
@@ -151,25 +155,25 @@ These properties are defined on `Iterator.prototype` and shared by all `Iterator
 ## Instance methods
 
 - {{jsxref("Iterator.prototype.drop()")}}
-  - : Returns a new iterator helper that skips the given number of elements at the start of this iterator.
+  - : Returns a new iterator helper object that skips the given number of elements at the start of this iterator.
 - {{jsxref("Iterator.prototype.every()")}}
   - : Tests whether all elements produced by the iterator pass the test implemented by the provided function.
 - {{jsxref("Iterator.prototype.filter()")}}
-  - : Returns a new iterator helper that yields only those elements of the iterator for which the provided callback function returns `true`.
+  - : Returns a new iterator helper object that yields only those elements of the iterator for which the provided callback function returns `true`.
 - {{jsxref("Iterator.prototype.find()")}}
   - : Returns the first element produced by the iterator that satisfies the provided testing function. If no values satisfy the testing function, {{jsxref("undefined")}} is returned.
 - {{jsxref("Iterator.prototype.flatMap()")}}
-  - : Returns a new iterator helper that takes each element in the original iterator, runs it through a mapping function, and yields elements returned by the mapping function (which are contained in another iterator or iterable).
+  - : Returns a new iterator helper object that takes each element in the original iterator, runs it through a mapping function, and yields elements returned by the mapping function (which are contained in another iterator or iterable).
 - {{jsxref("Iterator.prototype.forEach()")}}
   - : Executes a provided function once for each element produced by the iterator.
 - {{jsxref("Iterator.prototype.map()")}}
-  - : Returns a new iterator helper that yields elements of the iterator, each transformed by a mapping function.
+  - : Returns a new iterator helper object that yields elements of the iterator, each transformed by a mapping function.
 - {{jsxref("Iterator.prototype.reduce()")}}
   - : Executes a user-supplied "reducer" callback function on each element produced by the iterator, passing in the return value from the calculation on the preceding element. The final result of running the reducer across all elements is a single value.
 - {{jsxref("Iterator.prototype.some()")}}
   - : Tests whether at least one element in the iterator passes the test implemented by the provided function. It returns a boolean value.
 - {{jsxref("Iterator.prototype.take()")}}
-  - : Returns a new iterator helper that yields the given number of elements in this iterator and then terminates.
+  - : Returns a new iterator helper object that yields the given number of elements in this iterator and then terminates.
 - {{jsxref("Iterator.prototype.toArray()")}}
   - : Creates a new {{jsxref("Array")}} instance populated with the elements yielded from the iterator.
 - [`Iterator.prototype[Symbol.iterator]()`](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/Symbol.iterator)

files/en-us/web/javascript/reference/global_objects/iterator/map/index.md

@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Iterator.map
 
 {{JSRef}}
 
-The **`map()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) that yields elements of the iterator, each transformed by a mapping function.
+The **`map()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects) that yields elements of the iterator, each transformed by a mapping function.
 
 ## Syntax
 
@@ -26,7 +26,7 @@ map(callbackFn)
 
 ### Return value
 
-A new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers). Each time the iterator helper's `next()` method is called, it gets the next element from the underlying iterator, applies `callbackFn`, and yields the return value. When the underlying iterator is completed, the iterator helper is also completed (the `next()` method produces `{ value: undefined, done: true }`).
+A new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects). Each time the iterator helper's `next()` method is called, it gets the next element from the underlying iterator, applies `callbackFn`, and yields the return value. When the underlying iterator is completed, the iterator helper is also completed (the `next()` method produces `{ value: undefined, done: true }`).
 
 ## Description
 

files/en-us/web/javascript/reference/global_objects/iterator/take/index.md

@@ -7,7 +7,7 @@ browser-compat: javascript.builtins.Iterator.take
 
 {{JSRef}}
 
-The **`take()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) that yields the given number of elements in this iterator and then terminates.
+The **`take()`** method of {{jsxref("Iterator")}} instances returns a new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects) that yields the given number of elements in this iterator and then terminates.
 
 ## Syntax
 
@@ -22,7 +22,7 @@ take(limit)
 
 ### Return value
 
-A new [iterator helper](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers). The returned iterator helper yields the elements in the original iterator one-by-one, and then completes (the `next()` method produces `{ value: undefined, done: true }`) once `limit` elements have been yielded, or when the original iterator is exhausted, whichever comes first.
+A new [iterator helper object](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_objects). The returned iterator helper yields the elements in the original iterator one-by-one, and then completes (the `next()` method produces `{ value: undefined, done: true }`) once `limit` elements have been yielded, or when the original iterator is exhausted, whichever comes first.
 
 ### Exceptions
 

files/en-us/web/javascript/reference/iteration_protocols/index.md

@@ -128,7 +128,7 @@ There is no object in the core JavaScript language that is async iterable. Some
 
 [Generator functions](/en-US/docs/Web/JavaScript/Reference/Statements/function*) return [generator objects](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator), which are iterable iterators. [Async generator functions](/en-US/docs/Web/JavaScript/Reference/Statements/async_function*) return [async generator objects](/en-US/docs/Web/JavaScript/Reference/Global_Objects/AsyncGenerator), which are async iterable iterators.
 
-The iterators returned from built-in iterables actually all inherit from a common class {{jsxref("Iterator")}}, which implements the aforementioned `[Symbol.iterator]() { return this; }` method, making them all iterable iterators. The `Iterator` class also provides additional [helper methods](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) in addition to the `next()` method required by the iterator protocol. You can inspect an iterator's prototype chain by logging it in a graphical console.
+The iterators returned from built-in iterables actually all inherit from a common class {{jsxref("Iterator")}}, which implements the aforementioned `[Symbol.iterator]() { return this; }` method, making them all iterable iterators. The `Iterator` class also provides additional [helper methods](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_methods) in addition to the `next()` method required by the iterator protocol. You can inspect an iterator's prototype chain by logging it in a graphical console.
 
 ```plain
 console.log([][Symbol.iterator]());
@@ -303,7 +303,7 @@ The lack of `catch` here causes errors thrown by `doSomething()` or `doSomething
 
 ### Forwarding errors
 
-Some built-in syntaxes wrap an iterator into another iterator. They include the iterator produced by {{jsxref("Iterator.from()")}}, [iterator helpers](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helpers) (`map()`, `filter()`, `take()`, `drop()`, and `flatMap()`), [`yield*`](/en-US/docs/Web/JavaScript/Reference/Operators/yield*), and a hidden wrapper when you use async iteration (`for await...of`, `Array.fromAsync`) on sync iterators. The wrapped iterator is then responsible for forwarding errors between the inner iterator and the caller.
+Some built-in syntaxes wrap an iterator into another iterator. They include the iterator produced by {{jsxref("Iterator.from()")}}, [iterator helper methods](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator#iterator_helper_methods) (`map()`, `filter()`, `take()`, `drop()`, and `flatMap()`), [`yield*`](/en-US/docs/Web/JavaScript/Reference/Operators/yield*), and a hidden wrapper when you use async iteration (`for await...of`, `Array.fromAsync`) on sync iterators. The wrapped iterator is then responsible for forwarding errors between the inner iterator and the caller.
 
 - All wrapper iterators directly forward the `next()` method of the inner iterator, including its return value and thrown errors.
 - Wrapper iterators generally directly forward the `return()` method of the inner iterator. If the `return()` method doesn't exist on the inner iterator, it returns `{ done: true, value: undefined }` instead. In the case of iterator helpers: if the iterator helper's `next()` method has not been called, after trying to call `return()` on the inner iterator, the current iterator always returns `{ done: true, value: undefined }`. This is consistent with generator functions where execution hasn't entered the `yield*` expression yet.