"What are requirements"https://www.linkedin.com/grp/post/128312-6019368539587121153
A lot of comments already, have not read all of them, but i think the question is too wide. We need some adjectives in front of "requirement". I don't necessarily like all of them myself, but I offer up the ones I hear most: business, process, functional, non-functional , solution, system, even testing.
I think what most comments here are speaking to is the functional requirement. While precise wording can vary, I hold that the definition must emphasize the concept of "what, not how". I like Jose Santos version, but would shorten it to "A software requirement describes what a software should do but not how to do it, and it satisfies a need." I also like where commentators use the term "future". Certainly a requirement stated now implies a future state where it is met, but it is good to state/think it instead of assuming the implication.