Four to the floor

Four-on-the-floor (or four-to-the-floor) is a rhythm pattern used in disco and electronic dance music. It is a steady, uniformly accented beat in 4/4 time in which the bass drum is hit on every beat (1, 2, 3, 4) in common time. This was popularized in the disco music of the 1970s and the term four-on-the-floor was widely used in that era: it originated with the pedal-operated, drum-kit bass drum.

Many styles of electronic dance music, particularly those that are derived from house and techno, use this beat as an important part of the rhythmic structure. Sometimes the term is used to refer to a 4/4 uniform drumming pattern for any drum. A form of four-on-the-floor is also used in jazz drumming. Instead of hitting the bass drum in a pronounced and therefore easily audible fashion, it is usually struck very lightly (referred to as "feathering") so that the sound of the drum is felt instead of heard by the listener. Typically, this is combined with a ride cymbal and hi-hat in syncopation. When a string instrument makes the rhythm (rhythm guitar, banjo), all four beats of the measure are played by identical downstrokes.

In reggae drumming, the bass drum usually hits on the third beat but sometimes drummers play four on the floor. Sly Dunbar from Sly & Robbie was one of the reggae drummers who played mostly in this style. Also Carlton Barrett from Bob Marley & The Wailers played four on the floor on several hits by The Wailers like "Is This Love" and "Exodus". In reggae, four on the floor usually goes by the hand with a low end and powerful bassline. Four on the floor can be found in more modern reggae derivative styles such as dancehall, while it is less common to find it in roots reggae.

...
Wikipedia