Same brand, different battery
Greenworks also sells Greenworks 40V, Greenworks 60V and Greenworks 80V. We have no source saying their packs fit Greenworks 24V tools, so don't assume a shared brand means a shared battery.
The Greenworks 24V lineup
Greenworks 24V is Greenworks's cordless battery platform. PowerToolGrid lists 44 products in it: 8 batteries, 6 lawn mowers, 8 string trimmers, 8 leaf blowers and more. Prices on file run from $59.99 to $129.99.