The base is original from the producer (chords and melodies), but is complemented with elements that complement the song that come from samplepacks, usually, vocal chops, guitars, wobbles sections, glitch effects. It is the standard in which most of producers work, in a project you will find MIDI files made by the producer, but also melodic loops.
Groove and punch drums, hats and percs to improve the rhythm, tech house bassline made in Serum, guitar riffs and guitar licks on the sides, vintage royalty-free vocals and a lot of effects to fill the track.
Sample pack Vengeance Nu Disco Vol 1
Loop name VND Guitar Lick 27 Am 120Bpm