A:Answer Specs determine the difference, the A line usually goes A0x-A7x with 7 being the highest spec one of the lines. Goes A0x, A1x, A3x, A5x, A7x. Lower numbered ones usually have the older chipsets, camera, screen size/quality and least amount of ram/storage.
Second number, this case the x3 and x1 means revision/version. the A53 is are new for 2022, with a A33 & A73 floating out there but not for US carriers atm.