Do you have any aspirations in those subjects such as medicine, engineering etc..? Physics and Biology are very different, I've heard biology has ALOT of content to memorise and physics has less things to memorise and is much more maths is involved. Understanding the concepts in physics is key as exam questions will ask you to apply a mixture of different topics for one question. I can only speak for physics as I did it at A level. You will learn more about classical mechanics (everything to do with forces, gravity, momentum, moments etc..) electricity, particle physics, waves, thermal physics, fields and magnetism. Take a look at the exam board you would be doing and check on their websites the specification to see what you'd be studying.