The data migration assistant is a free and simple to use tool from Microsoft that allows you to assess and migrate databases from SQL Server to SQL Server or to Azure SQL. The tool is easy to use and provides considerable benefits over backing up and restoring the databases on the destination.
In addition to the migration of the databases, SQL logins can also be migrated between servers, this removes the need for additional scripts to be deployed and executed. The real power of the tool is the assessment of legacy databases this can be used to highlight compatibility issues and feature improvements that are available. This can provide invaluable insights and safe a lot of migration headaches.