is a specific kind of: grouping.

is a broader term that covers: agglomeration | collation | compilation, compiling | gather, gathering | bottle collection | conchology, shell collecting | coin collecting, coin collection, numismatics, numismatology | pickup | philately, stamp collecting, stamp collection | tax collection.

derivation: collect, garner, gather, pull together | collect, pull in | accumulate, amass, collect, compile, hoard, pile up, roll up.