An AK-74 is an assault rifle. The term was coined by the germans with the "Sturmgawer." It was the first select fire (semi or full automatic) rifle with an intermediate round.
The Automat Kalashnakov was a parallel development based on earlier but impracticle russian designs.
True Assualt Rifles are covered by the 1934 act restricting private ownership of automatic weapons. The 1994 ban fallaciously labelled scary-looking semi-automatic rifles as assault weapons.