What is ACDC chord?

The ACDC chord is the name of a power chord consisting of the root, fifth, and octave notes of any given key, played together and named using the root-fifth notation system that is common for power chords. The ACDC chord is so called because it is a common progression used by the rock band AC/DC, and is used in some of the band's most famous songs, including "Back in Black", "Highway to Hell", and "T.N.T.".