See Gather for the opposite effect. See Move for more general information.
Rules
Boosts to a Power's Range do not affect Pushing distance: Only pushes things to lands adjacent to the target.
May Push multiple things into multiple lands (or not): Pieces pushed may go to different lands, or all to the same land, as you wish.
Can only Push into a valid land: Not off the board or into the Ocean (unless Ocean's Hungry Grasp is in play and has presence on that board).
Push is a type of Move: And activates corresponding effects e.g. "After Invaders/ are Moved into target land, Destroy them." as in Melt Earth Into Quicksand.