Amazon S3
Amazon Simple Storage is a managed object store service provided by AWS. It is a distributed, high-scalable, high available cloud storage. It can be used in place of HDFS like your on-premise Hadoop data lakes where it becomes foundation of your data lake. It can also be used to store unstructured data, content and media, backups and archives and so on.
Cassandra Managed service
Amazon Managed Apache Cassandra Service is a scalable, highly available, and managed Apache Cassandra–compatible database service. Cassandra is very good for application which have very high throughput and supports faster reads when queries on primary or partition keys. It provides sub milliseconds response times.
Amazon ElastiCache
Amazon ElasticCache is managed service that supports Memcached and Redis implementations. This service improves performance of the web applications by allowing to store information in in-memory cache and then retrieve information from fast in-memory caches, instead of making multiple trips to slower backend databases.
This can also be used to store static content on web and also used as fast layer in lambda architecture.
Amazon DocumentDB
Amazon DocumentDB is a fully managed document-oriented database service which supports JSON data workloads. It is MongoDB compatible. Its fast, high available and scales over huge amounts of data.
Redshift
Amazon Redshift is a fast, fully managed analytical data warehouse database service scales over petabytes of data. Amazon Redshift provides a standard SQL interface that lets organizations use existing business intelligence and reporting tools. Amazon Redshift is a columnar database and distributed over multiple nodes allows to process requests parallel on multiple nodes.
Amazon RDS
Amazon Relational database service(RDS) provides a fully managed relational databases both open source and commercial database engines. It supports MySQL, PostgreSQL, Oracle, SQL Server and Amazon Aurora. You can also bring your own license if you have one internally. Amazon RDS manages all operations, support related tasks internally.
Amazon Dynamo
Amazon Dynamo is a distributed wide column NoSQL database can be used by application where it needs consistent and millisecond latency at any scale. It is fully managed and can be used for document and wide column data models. It also supports flexible schema and can be used for web, ecommerce, streaming, gaming and IOT use cases.