AWS Migration Hub
AWS Migration Hub is a single location that aids in tracking the application you are migrating. It visualizes the applications and DB you are looking to migrate.
Application Discovery Service
It is an automated set of tools that discovers the various applications you have. It also tries to understand and map the various dependencies between your applications.
Database Migration Service
It is an AWS service that simplifies the way to migrate your on-premises application to AWS.
Server Migration Services:
It helps in migrating your virtual and physical servers to AWS.