The last section was composed of programs that you can run at any time. However, the commands in this section usually make sense only in the context of a batch file. Although they all run outside of batch files, they usually aren't useful when used that way.
CALL is used to launch one batch file from another. It effectively is a GOSUB or function-like command because the source file halts until the called file completes running. Operation then resumes in the source file. By using the CALL :LABEL syntax, a different section in the same batch file can be called.