Microsoft offers several tools and approaches for migrating SQL Server to Azure and it’s easy to get confused.

Technology Description
Azure Migrate This Azure service helps you discover and assess your SQL data estate at scale on VMware. It provides Azure SQL deployment recommendations, target sizing, and monthly estimates.
Data Migration Assistant (DMA) This desktop tool from Microsoft provides seamless assessments of SQL Server and single-database migrations to Azure SQL Database (both schema and data).

The tool can be installed on a server on-premises or on your local machine that has connectivity to your source databases. The migration process is a logical data movement between objects in the source and target databases.

Azure Database Migration Service (DMS) This Azure service can migrate SQL Server databases to Azure SQL Database or Azure SQL Managed Instance (SQL MI) through the Azure portal or automatically through PowerShell. Database Migration Service requires you to select a preferred Azure virtual network during provisioning to ensure connectivity to your source SQL Server databases. You can migrate single databases or at scale.
Microsoft SQL Server Migration Assistant (SSMA) SSMA is a tool designed to automate database migration to SQL Server from Microsoft Access, DB2, MySQL, Oracle, and SAP ASE.
Database Experimentation Assistant (DEA) DEA is an experimentation solution for exploring options for SQL Server upgrades. DEA can help you evaluate a targeted version of SQL Server for a specific workload.

The capabilities of some of these tools are very similar. I wish some of these tools could be refactored and combined to reduce the confusion for Microsoft’s customers. This seems to be another example of a company’s organizational structure being pushed onto their customer base instead of the internal organizations working together to simplify product offerings.

Capability Azure Migrate Data Migration Assistant (DMA) SQL Server Migration Assistant (SSMA) Azure Database Migration Service (DMS) Database Experimentation Assistant (DEA)
Discover and assess SQL data estate At scale Yes No No No
Migrate SQL Server objects to SQL Database or SQL Managed Instance No Yes No Yes No
Lift and shift SQL Server to SQL Server on Azure VM Yes No No No No
Migrate (and/or upgrade) SQL Server to SQL Server on Azure VM No Yes No No No
Migrate non-SQL objects
(Oracle, Access, DB2, and so on)
No No Yes No No
Migrate open source databases
(MySQL, PostgreSQL, MariaDB, and so on)
No No No Yes No
Compare workloads between source and target SQL Server No No No No Yes