Imperative can mean: Imperative mood, a grammatical mood expressing commands, direct requests, and prohibitions; Imperative programming, a programming paradigm in computer science ...
In computer science, imperative programming, is a programming paradigm that describes computation in terms of statements that change a program state.
adjective . 1. absolutely necessary or required; unavoidable: It is imperative that we leave. 2. of the nature of or expressing a command; commanding.