It's a type of nice structure. Lists with concat, strings with append, etc. "Friendly chunkability", if you like. For instance, map reduce is a monoid homomorph

It's a type of nice structure. Lists with concat, strings with append, etc. "Friendly chunkability", if you like. For instance, map reduce is a monoid homomorphism - when I see 'monoid homomorphism' in the wild, I think 'parallelizable' etc. It's a handy concept.