Being new to the Dslr scene and still trying to decide what to buy for my first, see my introduction.
Im trying to get my head around what all the letters and numbers mean, could someone if you have time and sorry if the question has already been posted before what do all the numbers and letters mean on the following lens types
EF 70-200mm f/2.8 L IS II USM Lens f2.8
EF 70-300mm f/4-5.6 IS USM
AF 18-200mm f/3.5-6.3 XR Di II