The word scheme is similar to schema, and thus has numerous meanings based on the area of expertise and context of the user.
See conceptual scheme.
In the context of programming languages, the Scheme programming language is a streamlined variant of the Lisp programming language. It was originally to be called "Schemer," but the operating system on which it was first implemented had a six-character file name limit, so it was renamed "Scheme."
In mathematics, a scheme is a certain topological space, together with commutative rings for all its open sets, derived from the space of prime ideals of a commutative ring; it is an important concept connecting the fields of algebraic geometry, commutative algebra and number theory.