Here's my understanding of the terms:

passive means a plr allows others to take the lead - calling and checking and passive

aggressive means a plr leads - raising and folding are aggressive

I don't think it makes sense to play using one style the whole time. There are times is makes good sense to play one way or the other. There are also times when you could go either way. For instance if I am not sure I will go passive late in a hand. But I am generally aggressive early in a hand.

There are also loose and tight plrs. Loose means they play more hands and are will take more risk Tight means they are more selective and avoid risk. A loose plr will win more pots but may get trapped into losing a few big pots by a tight plr. A tight plr will win few pots but they will generally be bigger.