Classification is not entirely clear, tanks are usually the armored tracked vehicles armed with cannons placed in turrets. For example of controversy look at Swedish Stridsvagn 103 which is usually called tank despite technically it is rather tank destroyer.
ISU-152 is usually classified as “assault cannon” since it’s basically an armored mobile howitzer used to fire directly.
Why is it not a tank?
Classification is not entirely clear, tanks are usually the armored tracked vehicles armed with cannons placed in turrets. For example of controversy look at Swedish Stridsvagn 103 which is usually called tank despite technically it is rather tank destroyer.
ISU-152 is usually classified as “assault cannon” since it’s basically an armored mobile howitzer used to fire directly.