As stated before, iCloud automatically makes a copy of all your musical *iTunes purchases* available to your other devices.
iTunes Match, on the other hand, makes your entire *iTunes library,* including songs from CDs et al, available to all your devices (via some kind of internet connection obviously). iTunes Match costs $25/year and has a limit of 25,000 non-iTunes-purchased songs (iTunes purchases don't count against that limit, iow).