Revise wording and incorrect content (#2543)

docs/books/admin_guide/09-backups.md

@@ -217,8 +217,8 @@ Here is an example of a naming convention for a `tar` backup, knowing that the d
 | `cvfP`  | `/etc`  | `etc.A.tar`      | `/etc` in absolute mode, no compression      |
 | `cvfz`  | `usr`   | `usr.tar.gz`     | `/usr` in relative mode, *gzip* compression  |
 | `cvfj`  | `usr`   | `usr.tar.bz2`    | `/usr` in relative mode, *bzip2* compression |
-| `cvfPz` | `/home` | `home.A.tar.gz`  | `home` in absolute mode, *gzip* compression  |
-| `cvfPj` | `/home` | `home.A.tar.bz2` | `home` in absolute mode, *bzip2* compression |
+| `cvfPz` | `/home` | `home.A.tar.gz`  | `/home` in absolute mode, *gzip* compression  |
+| `cvfPj` | `/home` | `home.A.tar.bz2` | `/home` in absolute mode, *bzip2* compression |
 | …       |         |                  |                                        |
 
 #### Create a backup
@@ -245,7 +245,7 @@ Example:
 
 !!! Tip
 
-    The hyphen (`-`) in front of the `tar` keys is unnecessary!
+    The hyphen (`-`) in front of the `tar` keys is optional!
 
 ##### Create a backup in absolute mode
 
@@ -267,7 +267,7 @@ Example:
 
 !!! Warning
 
-    With the `P` key, the path of the files to be backed up must be entered as **absolute**. If the two conditions (key `P` and path **absolute**) are not indicated, the backup is in relative mode.
+    With the `P` key, the path of the files to be backed up must be entered as **absolute**. If the two conditions (`P` key and **absolute** path) are not indicated, the backup is in relative mode.
 
 ##### Creating a compressed backup with `gzip`
 
@@ -289,9 +289,9 @@ tar cvzf backup.tar.gz dirname/
 
     Keeping the `cvf` (`tvf` or `xvf`) keys unchanged for all backup operations and simply adding the compression key to the end of the keys makes the command easier to understand (such as: `cvfz` or `cvfj`, and others).
 
-##### Creating a compressed backup with `bzip`
+##### Creating a compressed backup with `bzip2`
 
-Creating a compressed backup with `bzip` is done with the keys `cvfj`:
+Creating a compressed backup with `bzip2` is done with the keys `cvfj`:
 
 ```bash
 tar cvfj backup.tar.bz2 dirname/
@@ -305,7 +305,7 @@ tar cvfj backup.tar.bz2 dirname/
 
     The `.tbz` and `.tb2` extensions are equivalent to `.tar.bz2` extensions.
 
-##### Compression `compress`, `gzip`, `bzip2`, `lzip` and `xz`
+##### Comparison of compression efficiency
 
 Compression, and consequently decompression, will impact resource consumption (time and CPU usage).
 
@@ -339,8 +339,8 @@ tar rvf backup_name.tar dirtoadd
 
 | Key | Description                                                                      |
 |-----|----------------------------------------------------------------------------------|
-| `r` |Adds one or more files at the end of a direct access media backup (hard disk).   |
-| `A` |Adds one or more files at the end of a backup on sequential access media (tape). |
+| `r` | Append the files or directories to the end of the archive.                       |
+| `A` | Append all files in one archive to the end of another archive.         |
 
 !!! Note
 
@@ -378,19 +378,19 @@ tar tvfz backup.tar.gz
 tar tvfj backup.tar.bz2
 ```
 
-When the number of files in a backup becomes large, it is possible to *pipe* the result of the `tar` command to a *pager* (`more`, `less`, `most`, and others):
+When the number of files in the backup increases, you can use pipe characters (`|`) and some commands (`less`, `more`, `most`, and others) to achieve the effect of paging viewing:
 
 ```bash
 tar tvf backup.tar | less
 ```
 
 !!! Tip
 
-    To list or retrieve the contents of a backup, it is not necessary to mention the compression algorithm used when the backup was created. That is, a `tar tvf` is equivalent to `tar tvfj`, to read the contents, and a `tar xvf` is equivalent to `tar xvfj`, to extract.
+    To list or retrieve the contents of a backup, it is not necessary to mention the compression algorithm used when the backup was created. That is, a `tar tvf` is equivalent to `tar tvfj`, to read the contents. The compression type or algorithm **must** only be selected when creating a compressed backup.
 
 !!! Tip
 
-    Always check the contents of a backup.
+    You should always check and view the contents of the backup file before performing a restore operation.
 
 #### Check the integrity of a backup
 

docs/guides/backup/tar.md

@@ -61,7 +61,7 @@ The usage to extract a file from an archive is:
 
 | types | describe |
 | :---: | :--- |
-| `-A`  | Merge the current archive with an existing archive. Only applicable to archive non-compressed files of the `.tar` type |
+| `-A`  | Append all files in one archive to the end of another archive. Only applicable to archive non-compressed files of the `.tar` type |
 | `-c`  | Create archive. Very commonly used  |
 | `-d`  | Compare the differences between archived and corresponding unarchived files |
 | `-r`  | Append the files or directories to the end of the archive. Only applicable to archive non-compressed files of the `.tar` type  |
@@ -147,8 +147,8 @@ Here are examples of naming conventions for `tar` archives:
 | `-cvfP`  | `/etc`  | `etc.A.tar`      | `/etc` in absolute mode, no compression      |
 | `-cvfz`  | `usr`   | `usr.tar.gz`     | `/usr` in relative mode, *gzip* compression  |
 | `-cvfj`  | `usr`   | `usr.tar.bz2`    | `/usr` in relative mode, *bzip2* compression |
-| `-cvfPz` | `/home` | `home.A.tar.gz`  | `home` in absolute mode, *gzip* compression  |
-| `-cvfPj` | `/home` | `home.A.tar.bz2` | `home` in absolute mode, *bzip2* compression |
+| `-cvfPz` | `/home` | `home.A.tar.gz`  | `/home` in absolute mode, *gzip* compression  |
+| `-cvfPj` | `/home` | `home.A.tar.bz2` | `/home` in absolute mode, *bzip2* compression |
 
 You may also add the date to the filename.
 
@@ -238,7 +238,7 @@ You may also add the date to the filename.
     Shell > tar -Avf /tmp/etc.tar /tmp/log.tar
     ```
 
-    This means appending "log.tar" to "etc.tar".
+    This means that all files in "log.tar" will be appended to the end of "etc.tar".
 
 2. Append files or directories to a `.tar` file: