Fixed some typos, deleted repeated words

README.md

@@ -873,7 +873,7 @@ CloudWatch
 		* Monitor and report on EC2 [instance system check failure alarms](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html#creating_status_check_alarms).
 * **Using CloudWatch Events:**
     * Events create a mechanism to automate actions in various services on AWS. You can create [event rules](http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/EventTypes.html) from instance states, AWS APIs, Auto Scaling, Run commands, deployments or time-based schedules (think Cron).
-    * [Triggered events](http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/CWE_GettingStarted.html) can can invoke Lambda functions, send SNS/SQS/Kinesis messages, or perform instance actions (terminate, restart, stop, or snapshot volumes).
+    * [Triggered events](http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/CWE_GettingStarted.html) can invoke Lambda functions, send SNS/SQS/Kinesis messages, or perform instance actions (terminate, restart, stop, or snapshot volumes).
     * Custom payloads can be sent to targets in JSON format, this is especially useful when triggering Lambdas.
 * **Using CloudWatch Logs:**
     * [CloudWatch Logs](http://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/WhatIsCloudWatchLogs.html) is a streaming log storage system. By storing logs within AWS you have access to unlimited paid storage, but you also have the option of streaming logs directly to ElasticSearch or custom Lambdas.
@@ -1383,7 +1383,7 @@ Fargate
 -   Fargate allows you to treat containers as fundamental building blocks of your infrastructure
 
 ### Fargate Tips
--   Fargate follows a similar mindset to Lambda, which lets you focus on applications, instead of dealing with undelying infrastructure
+-   Fargate follows a similar mindset to Lambda, which lets you focus on applications, instead of dealing with underlying infrastructure
 -   Fargate is supported by CloudFormation, aws-cli and ecs-cli
 -   Fargate tasks can be launched alongside tasks that use EC2 Launch Type
 -   💸Before creating a large Fargate deployment, make sure to estimate costs and compare them against alternative solution that uses traditional EC2 deployment - Fargate prices can be several times those of equivalently-sized EC2 instances. To evaluate both solutions based on potential costs, refer to pricing for [EC2](https://aws.amazon.com/ec2/pricing/) and [Fargate](https://aws.amazon.com/fargate/pricing/).
@@ -1409,7 +1409,7 @@ Lambda
 
 -	The idea behind 'serverless' is that users don't manage provisioning, scaling, or maintenance of the physical machines that host their application code. With Lambda, the machine that actually executes the user-defined function is abstracted as a ['container'](http://docs.aws.amazon.com/lambda/latest/dg/lambda-introduction.html). When defining a Lambda function, users are able to declare the amount of memory available to the function, which directly affects the physical hardware specification of the Lambda container.
 -	Changing the amount of memory available to your Lambda functions also affects the amount of [CPU power](https://aws.amazon.com/lambda/faqs/) available to it.
--	While AWS does not offer hard guarantees around container reuse, in general it can be expected that an unaltered Lambda function will reuse a warm (previously used) container if called shortly after another invocation. Users can use this as a way to optimize their funtions by smartly caching application data on initialization.
+-	While AWS does not offer hard guarantees around container reuse, in general it can be expected that an unaltered Lambda function will reuse a warm (previously used) container if called shortly after another invocation. Users can use this as a way to optimize their functions by smartly caching application data on initialization.
 -	A Lambda that hasn't been invoked in some time may not have any warm containers left. In this case, the Lambda system will have to load and initialize the Lambda code in a 'cold start' scenario, which can add significant latency to Lambda invocations.
 -	There are a few strategies to avoiding or mitigating cold starts, including keeping containers warm by periodic triggering and favoring lightweight runtimes such as Node as opposed to Java.
 -	Lambda is integrated with AWS CloudWatch and provides a logger at runtime that publishes CloudWatch events.
@@ -1435,7 +1435,7 @@ Lambda
 - 🔸While adding/removing S3 buckets as triggers for Lambda function, this error may occur: "There was an error creating the trigger: Configuration is ambiguously defined. Cannot have overlapping suffixes in two rules if the prefixes are overlapping for the same event type." In this case, you can manually remove the Lambda event in the "Events" tab in the "Properties" section of the S3 bucket.
 - 🔸Managing the size of your deployment artifact can be a challenge, especially if using Java. Options to mitigate this include [proguard](https://www.guardsquare.com/en/proguard) and loading dependencies at runtime into /tmp.
 - When using DynamoDB as a trigger for your Lambda functions, this error may occur: "PROBLEM: internal Lambda error. Please contact Lambda customer support." This usually just means that Lambda can't detect anything in the DynamoDB stream within the last 48 hours. If the issue persists, deleting and recreating your trigger may help.
-- 🔸If your lambda needs access to resources in a VPC (for example ElastiCache or RDS), it will need to be deployed within it. This will increase cold-start times as an Elastic Network Interface (ENI) will have to be registered within the VPC for each concurrenat function. AWS also has a relatively low initial limit (350) on the number ENI's that can be created within an VPC, however this can be increased to the 1000s if a good case is made to AWS support.
+- 🔸If your lambda needs access to resources in a VPC (for example ElastiCache or RDS), it will need to be deployed within it. This will increase cold-start times as an Elastic Network Interface (ENI) will have to be registered within the VPC for each concurrent function. AWS also has a relatively low initial limit (350) on the number ENI's that can be created within an VPC, however this can be increased to the 1000s if a good case is made to AWS support.
 -	🔸 Lambda has several [**resource limits**](http://docs.aws.amazon.com/lambda/latest/dg/limits.html) as of 2017-06:
 	-	A **6MB** request or response payload size.
 	-	A **50 MB** limit on the compressed .zip/.jar file deployment package size.
@@ -1519,7 +1519,7 @@ Step Functions
 
 ### Step Functions Gotchas and Limitations
 -   Step Functions are free tier eligible up to an initial 4000 transitions per month. Thereafter, the charge is $0.025 per 1000 state transitions.
--   You can have many, simulatanous, executions, but be aware of lambda throttling limits. This has been per-account, pre-region, but recently became settable per-lambda.
+-   You can have many, simultaneous, executions, but be aware of lambda throttling limits. This has been per-account, pre-region, but recently became settable per-lambda.
 
 Route 53
 --------
@@ -1546,7 +1546,7 @@ Route 53
 	-	Somewhat confusingly, you can have CNAME and A aliases, depending on the type of the target.
 	-	Because aliases are extensions to regular DNS records, if exported, the output [zone file](https://en.wikipedia.org/wiki/Zone_file) will have additional non-standard “ALIAS” lines in it.
 -	[**Latency-based routing**](https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/routing-policy.html#routing-policy-latency) allows users around the globe to be automatically directed to the nearest AWS region where you are running, so that latency is reduced.
--	Understand that domain registration and DNS management (hosted zones) are two separate Route 53 services. When you buy/transfer a domain, Route 53 automaticaly assigns four name servers to it (e.g. ns-2.awsdns-00.com). Route 53 also offers to automatically create a hosted zone for DNS management, but you are not required do your DNS management in the same account or even in Route 53; you just need to create an NS record pointing to the servers assigned to your domain in Route 53.
+-	Understand that domain registration and DNS management (hosted zones) are two separate Route 53 services. When you buy/transfer a domain, Route 53 automatically assigns four name servers to it (e.g. ns-2.awsdns-00.com). Route 53 also offers to automatically create a hosted zone for DNS management, but you are not required do your DNS management in the same account or even in Route 53; you just need to create an NS record pointing to the servers assigned to your domain in Route 53.
   - One use case would be to put your domain registration (very mission critical) in a [bastion account](https://cloudonaut.io/your-single-aws-account-is-a-serious-risk/) while managing the hosted zones within another account which is accessible by your applications.
 
 CloudFormation
@@ -1588,7 +1588,7 @@ CloudFormation
 -	🔹Until [2016](https://aws.amazon.com/about-aws/whats-new/2016/09/aws-cloudformation-introduces-yaml-template-support-and-cross-stack-references/), CloudFormation used only an awkward JSON format that makes both reading and debugging difficult. To use it effectively typically involved building additional tooling, including converting it to YAML, but now [this is supported directly](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-formats.html).
 - Wherever possible, export relevant [physical IDs](http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-name.html) from your Stacks by defining [Outputs in your CloudFormation Templates](http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/outputs-section-structure.html). These are the actual names assigned to the resources being created. Outputs can be returned from `DescribeStack` API calls, and get imported to other Stacks as part of the [recent addition](https://aws.amazon.com/about-aws/whats-new/2016/09/aws-cloudformation-introduces-yaml-template-support-and-cross-stack-references/) of [cross-stack references](http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/walkthrough-crossstackref.html).
 	-Note that importing outputs in a stack from another stack creates a hard dependency that is tracked by CloudFormation. You will not be able to delete the stack with the outputs until there are no importing stacks.
--	CloudFormation can be set up to [send SNS notifications](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-console-add-tags.html) upon state changes, enabling programatic handling of situations where stacks fail to build, or simple email alerts so the appropriate people are informed.
+-	CloudFormation can be set up to [send SNS notifications](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-console-add-tags.html) upon state changes, enabling programmatic handling of situations where stacks fail to build, or simple email alerts so the appropriate people are informed.
 -	CloudFormation allows the use of [**conditionals**](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/conditions-section-structure.html) when creating a stack.
 	-	One common way to leverage this capability is in support of multi-environment CloudFormation templates – by configuring them to use ‘if-else’ statements on the value of a [parameter passed in](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/parameters-section-structure.html) (e.g.  “env”), environment-specific values for things like VPC IDs, SecurityGroup IDs, and AMI names can be passed into reusable generic templates.
 -	**Version control your CloudFormation templates!** In the Cloud, an application is the combination of the code written and the infrastructure it runs on. By version controlling **both**, it is easy to roll back to known good states.
@@ -1652,7 +1652,7 @@ VPCs, Network Security, and Security Groups
 -	❗Be careful with VPC VPN credentials! If lost or compromised, the VPN endpoint must be deleted and recreated. See the instructions for [Replacing Compromised Credentials](http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_VPN.html#CompromisedCredentials).
 -	❗Security Groups and Route Tables apply entries separately for IPv4 and IPv6, so one must ensure they add entries for both protocols accordingly.
 - 	💸Managed NAT gateways are a convenient alternative to 
-manually managing [NAT instances](https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPCNATInstance.html), but they do come at a cost per gigabyte. Consider [alternatives](http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-nat-comparison.html) if you're transferring many terrabytes from private subnets to the internet.
+manually managing [NAT instances](https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPCNATInstance.html), but they do come at a cost per gigabyte. Consider [alternatives](http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-nat-comparison.html) if you're transferring many terabytes from private subnets to the internet.
 
 KMS
 ---
@@ -2087,7 +2087,7 @@ SQS
 - SQS supports the pull model, where the producers *queue* the messages, and the consumers pull messages off the queue.
 - SQS provides a message visibility timeout, during which the message being processed will not be delivered to other consumers. If the consumer does not delete the message after processing, the message becomes available to other consumers upon reaching the message visibility timeout. This parameter is called VisibilityTimeout.
 - Each message can have up to 10 custom fields, or attributes.
-- SQS allows producers to set up to to 15 minutes of delay before the messages are delivered to the consumers. This parameter is called DelaySeconds.
+- SQS allows producers to set up to 15 minutes of delay before the messages are delivered to the consumers. This parameter is called DelaySeconds.
 - There are two types of queues supported by SQS -
     - Standard Queues
         - Guarantee **at least once** delivery of the messages.