Trample means that damage carries through a defender or a group of them. I.e., Crash of Rhinos are, like, 6/4 with Trample and you attack Jebus with them. He blocks your Crash with a 1/1 Bog Imp. Normally, combat would end there. Instead, your Crash deals 1 damage to the Imp, kills it, and the other 5 damage carries on to the player.
Multiple blockers word on the same idea. If you kill all the blockers and have power left over, let's say you're blocked by a 1/1 and 3/4, the Crash of Rhinos kill them both (dies itself too, 'cause the blockers dealt it enough damage) and 1 damage carries onto your opponent.
I think I explained that adequately.
I'm going to see if I can even connect to someone before concretely saying I am in.