Amazon CloudWatch vs AWS CloudTrail: What are the differences?

What is Amazon CloudWatch? Monitor AWS resources and custom metrics generated by your applications and services. With Amazon CloudWatch, you gain system-wide visibility into resource utilization, application performance, and operational health. Programmatically retrieve your monitoring data, view graphs, and set alarms to help you troubleshoot, spot trends, and take automated action based on the state of your cloud environment.

What is AWS CloudTrail? Record AWS API calls for your account and have log files delivered to you. With CloudTrail, you can get a history of AWS API calls for your account, including API calls made via the AWS Management Console, AWS SDKs, command line tools, and higher-level AWS services (such as AWS CloudFormation). The AWS API call history produced by CloudTrail enables security analysis, resource change tracking, and compliance auditing. The recorded information includes the identity of the API caller, the time of the API call, the source IP address of the API caller, the request parameters, and the response elements returned by the AWS service.

Amazon CloudWatch belongs to "Cloud Monitoring" category of the tech stack, while AWS CloudTrail can be primarily classified under "Log Management".

Some of the features offered by Amazon CloudWatch are:

• Basic Monitoring for Amazon EC2 instances: ten pre-selected metrics at five-minute frequency, free of charge.
• Detailed Monitoring for Amazon EC2 instances: seven pre-selected metrics at one-minute frequency, for an additional charge.
• Amazon EBS volumes: eight pre-selected metrics at five-minute frequency, free of charge.

On the other hand, AWS CloudTrail provides the following key features:

• Increased Visibility- CloudTrail provides increased visibility into your user activity by recording AWS API calls. You can answer questions such as, what actions did a given user take over a given time period? For a given resource, which user has taken actions on it over a given time period? What is the source IP address of a given activity? Which activities failed due to inadequate permissions?
• Durable and Inexpensive Log File Storage- CloudTrail uses Amazon S3 for log file storage and delivery, so log files are stored durably and inexpensively. You can use Amazon S3 lifecycle configuration rules to further reduce storage costs. For example, you can define rules to automatically delete old log files or archive them to Amazon Glacier for additional savings.
• Easy Administration- CloudTrail is a fully managed service

"Monitor aws resources" is the primary reason why developers consider Amazon CloudWatch over the competitors, whereas "Very easy setup" was stated as the key factor in picking AWS CloudTrail.

Airbnb, 9GAG, and Asana are some of the popular companies that use Amazon CloudWatch, whereas AWS CloudTrail is used by Netflix, Slack, and Seat Pagine Gialle. Amazon CloudWatch has a broader approval, being mentioned in 721 company stacks & 334 developers stacks; compared to AWS CloudTrail, which is listed in 38 company stacks and 11 developer stacks.