Access official documentation at: https://docs.microsoft.com/en-us/sql/azure-data-studio/what-is?view=sql-server-ver15
Download: Microsoft SQL Server 2019 – Technical white paper
Additionally, you can obtain the whole SQL Server documentation as a pdf: https://docs.microsoft.com/en-us/sql/opbuildpdf/ab252483/toc.pdf?branch=live&view=sql-server-ver15 (it takes a while…)