(For a description of the mathematical term object language, see formal system.)
The programming language a programmer codes in is said to be an object language. In order for the machine to run the code the programmer writes, it has to be compiled, assembled, and interpreted. In the process, code itself becomes other intermediate languages (such as assembly language) before becoming a binary program that the computer can run.
The languages the code becomes during these intermediate stages and the final machine language are referred to as meta languages.