As far as I know, in Final Fantasy Tactics, the enemies grow stronger as the party members level up, like in Final Fantasy VIII.
For example, in Final Fantasy VIII, T-Rex is a whole lot stronger than a party member whose level is at...let's say 75. T-Rex can still be defeated while in level 1, but it will take some time to defeat T-Rex; however, it doesn't mean it will take less time to defeat T-Rex while at level 75.
Yupp that's called "Experience building up the level of each characters", actually all of Final Fantasy series does that, not only VIII.
Also about Final Fantasy Tactics, it's more stragey than RPG. That's all I know.