Q: Passage: Azure SQL Database shares the SQL Server 2016 codebase. It is compatible with SQL Server 2014 and 2016 and most of the features available in SQL Server 2016 are available in Azure SQL Database. A list of incompatibilities is published by Microsoft.

Question: Based on this passage, what version of sql server does azure use? Let's give stream of consciousness first:
The important part for answering this question is: Azure SQL Database shares the SQL Server 2016 codebase. Therefore, the final answer is the SQL Server 2016 codebase.