There are online slots which have a multispin feature. It means that you spin more than one spin to hit combinations of symbols. As a rule the multispin slots have such additional features, as HOLD or NUDGE.
The object of multispin slots as well as in other slot machines, is to receive an winning symbols combination. But in this slots you have a chance to operate two and more spins of reels (with buttons HOLD or-and NUDGE) before hit the last combination of symbols.
Various softwares have a different multispin slots. In PlayTech they are N-Reel N-Row Multispin Slots. In Microgaming they are AWP or Fruit Slots. In Wagerlogic they are Fruit Slots.