Before revision: A macro whacro in tacro computer science is a rule or pattern that specifies how a certain input sequence (often a sequence of characters) should be mapped to a replacement input sequence (also often a sequence of characters) according to a defined procedure.
After revision: A macro in computer science is a rule or pattern that specifies how a certain input sequence (often a sequence of characters) should be mapped to a replacement input sequence (also often a sequence of characters) according to a defined procedure.