Each interface library communicates with the database server using a communication protocol. SQL Anywhere supports two communication protocols, Command Sequence and Tabular Data Stream (TDS). These protocols are internal, and for most purposes it does not matter which one you are using. Your choice of development environment will be governed by your available tools.

The major differences are visible when connecting to the database. Command Sequence applications and TDS applications use different methods to identify a database and database server, and so connection parameters are different.