Argot is language particular to a specific group. It can mean a kind of slang, a technical language or a code. In high school, only those who spend their time studying computer manuals could understand the argot of the computer lab kids.
The word argot was originally used to describe the slang of thieves and rogues, who spoke in sneaky ways that the upright citizen couldn’t understand. We can also use argot to describe less criminal kinds of vocabularies. Any specialized practice can create an argot: boxers talk of bodyshots and jabs, just as grammar teachers complain of split infinitives and dangling participles.