"SUB A, B" refers to a type of programming construct used in various coding languages. It allows developers to create a subroutine, or a smaller section of code, that can be called multiple times within a program. This helps in organizing code, making it more efficient and easier to read. In the context of software development, "SUB A, B" typically indicates that the subroutine named A is being executed with B as an argument. This means that the subroutine will perform its defined tasks using the data or parameters provided by B.