Push
To push is to bet all your chips, going all in. The word also describes a pot that is tied or split between players, so nobody wins more than their own bet.
The simple explanation
Players say 'I'm pushing' when they put in all their chips. In some games, a push is also a tie, in which the players share the pot. The meaning depends on the situation.
A closer look
A push, as an all-in, is common in tournaments with short stacks: 'push or fold' is the standard strategy at around 10 big blinds or fewer. The decision is based on stack size, position and the ranges of the callers. In betting terms, a push means a tie in which the stakes are returned. Hand histories usually say 'shoves' or 'jams' for the all-in.
A practical example
With 8 big blinds left, a player pushes all in with A♦ 9♣ from the cutoff.
Full explanation
To push is to bet all your chips, going all in. The word also describes a pot that is tied or split between players, so nobody wins more than their own bet.
To push means to go all in.
It can also mean a split pot.
Push or fold is a short-stack strategy.
Jam and shove mean the same.