A "Scatter" is a special symbol found in many slot games. Unlike regular symbols that must align on a specific payline to award a win, Scatter symbols can appear anywhere on the reels and still provide a payout or unlock special features. These special features can include free spins, bonus rounds, or multipliers.
The specific rules for Scatter symbols vary from game to game. In some slots, you might need a certain number of Scatter symbols to appear in a single spin to unlock these features. It's always important to check the specific rules of the slot game you're playing to understand how its Scatter symbols work.