15. S3

S3 is one of the very first AWS services and is an object store. You create buckets and you can store an unlimited number of objects in a bucket.

Over the years, AWS has added many features to S3. There are now many different levels of storage options within S3. These options vary between the cost of use and time or frequency to retrieve objects stored there. AWS has features to execute Lambda functions on the creation, updating or deleting of objects. You can also automatically move or delete objects based on the time that they have been in a bucket with a lifecycle policy.