The tab located between the two screw terminals of an electrical outlet can be used to separate the top receptacle from the bottom receptacle, creating a "switched outlet" where a wall switch controls which receptacle is powered.
Speed wiring is a common method of installing an outlet, but it is not recommended as it only works with 14 gauge solid core wire and does not use the screw terminals for stability.
The screw terminals are not associated with holding the wire in place when using speed wiring, it is held in place by the tab in the hole.
Speed wiring is a one-time use feature, once the wire is removed it should not be used again for speed wiring, as it may result in loose connection due to deformation of tab that holds the wire in place.
Alternative methods such as back wiring, where a straight strand of conductor wire is used, is a recommended way to wire an outlet.
Speed wiring is a feature that is called different things by different brands
To confirm if the wire is 14 gauge, use the nickel and dime trick by comparing the thickness of a dime to the wire. If it matches, the wire is 14 gauge, if it matches with a nickel, the wire is 12 gauge.
Leave the screw terminal tighten even if you are not using speed wiring because it will help to prevent any loose connections.
Speed wiring can be removed by inserting a screwdriver in the slot and remove the wire.
Use speed wiring only once because it can deform the tab in the hole, that is holding the wire, resulting in a loose connection.