Tournament hands are played for tournament chips (not money) which only becomes money if/when you make it deep.
Tournaments are softer fields with a fixed risk (the tournament buy-in)
Tournaments also do not reward gambling in the way that cash does.
Tournaments are won by tight players in almost all circumstances and luck plays more of a factor in large tournaments due to blinds outpacing stack growth, so you will end up having to all in preflop ALOT more in a tournament then you ever will in cash games.
Cash tables are completely different.
Cash tables are more about knowing the math of odds
-to-call, pot odds
, implied odds, and risk vs reward. Gambling/bluffing/and advanced play are MUCH more common at cash tables.
Cash tables also have the potential to pay of much greater/faster then playing a tournament, so if your strictly interested in "potential gains" then cash games (even heads up play) is where its at.
The risk is far greater at a cash table, as your potentially risking your entire bankroll since you have the ability to "reload" unlike in a tournament.