Snap call
A snap call is when a player calls a bet instantly, with no pause to think, usually because the decision feels obvious to them.
A snap call happens when someone matches a bet right away, the moment it's their turn, instead of taking time to weigh the decision. The "snap" just describes the speed; the action itself is an ordinary call. It signals that the player already knew what they were going to do before the bet even landed.
You'll see it most when a hand is easy. A player who flopped a monster or holds a draw they're always continuing with may snap call to keep things moving. It also shows up when a bet is so small relative to the pot that calling is automatic. The opposite is a slow, drawn-out call where someone genuinely has to think it through.
As a beginner, don't read too much into how fast an opponent acts, and don't try to fake a snap call to look strong. Quick actions can be honest or staged, so they're an unreliable tell. Focus on whether your hand and your pot odds justify the call, not on matching anyone's tempo.
Example
You hold A-K and the flop comes A-K-7, giving you top two pair (aces and kings). An opponent shoves 60 chips into a 90-chip pot, and you snap call instantly because folding such a strong hand never crossed your mind.