All-Ins

What happens when someone pushes every chip in.

Table stakes. You play only the chips in front of you when the hand starts. No reaching into your pocket mid-hand.
Blinds and deal. Layla posts 1, Zofia posts 2. Cards come out. You have two kings.
You raise. You act first and raise to 6.
All in. Darius pushes every chip he has: 25. That is an all-in. He can never be asked for more than that.
Your options. Layla and Zofia fold. Back to you. Tap one to see what it means. With two kings, you call.
No more betting. Darius has no chips left to bet, and everyone else folded. So the dealer deals the flop, turn and river with no betting in between.
The board. Flop, turn, river, one after another. Pot: 25 from you, 25 from Darius, plus the 3 in blinds. 53 chips.
Showdown. Darius shows ace and queen of clubs. No pair. Your kings win.
You win. You take the 53-chip pot: 68 chips now. Darius is out of chips. In a cash game he can buy more before the next hand.

Play money only. Room rules differ, so ask the dealer when in doubt.