A Command Line Interface is a user interface composed of a prompt at which users may enter a command, terminated by <Return>
It can also refer to the syntax the arguments and options that such commands accept. For example, the tclsh Command Line Interface is: tclsh ?fileName ?arg??
Microsoft generally uses CLI to mean "Common Language Interface", part of the .NET amalgam [explain] [also distinguish from CLR.].
ECMA uses CLI (also in the context of .NET) for Common Language Infrastructure [L1 ].
SQL/CLI is the acronym for the standard SQL "Call-Level Interface", the best known implementation of which is ODBC.