CLOUDWATCH EVENTS: - Respond to actions (changes in your AWS environment).Example :- Lambda being created, CodePipeline state changes, etc.
CLOUDWATCH ALARMS:- Watch a single metric and respond to changes in that metric
CloudWatch Events allows you to trigger a number of events based on a specific schedule (think cronjob) or based on some event that happened in your AWS account. For example, if you want to trigger an SNS notification every time a user logs into the AWS Console.
CloudWatch Alarms collects standard metrics from your instances, S3 buckets, almost all the AWS services. You can add a threshold that triggers an action. For example, if your S3 bucket object count is greater than 100 then trigger a Lambda function to process the objects.
CLOUDWATCH EVENTS: - Can self-trigger based on a schedule (Cron jobs)
CLOUDWATCH ALARMS:- Can't do self-trigger based on schedule
CLOUDWATCH EVENTS: - Can be added to CloudWatch dashboards
CLOUDWATCH ALARMS:- Can't add to CloudWatch dashboards
Some other key points:
MVP - Early Version of your product/service to get insights from your customers.