A full-body invincible hitbox is invincible to all strikes as long as it lasts.
The main thing to watch out for, though, is that unlike complete invincibility, most full-body invincibility still has a throw-taking hitbox, leaving the “invincible” character still quite vulnerable during their invincibility.
Of course, since there is plenty of room for confusion between the two terms, you should not assume either way when reading a description. You should read these kind of things critically, lest you learn something erroneous.