both forms of poker are a form of gambling in their own sense. the difference is poker allows players to be in control of the risks they take.
the difference between cash game and tournaments are, while players are in control of the risks they take, they're forced to take more risks in tournaments because of raising blinds. where as, in cash games, they're never in that position. for that reason, tournament players have to be willing to take more risks more often in order to do well.