All of the commands included in the CQL language are available on the cqlsh command line. There are a group of commands that are available on the command line, but are not support by the CQL language. These commands are called cqlsh commands. You can run cqlsh commands from the command line only. You can run CQL commands in a number of ways.
This reference covers CQL and cqlsh based on the CQL specification 3.1.0.