okayyy

1.
Telephoto lens - basically a fancy name for a long zoom lens. the 'tele' bit basicly says it all, think of a telescope. allows you to get nice close up images whilst being a fair way away. and basically the higher the 'mm' length of the lens (100-500mm etc) the further the zoom will be. handy for things like motor sport/scenery/perving on shit really. and can be very expensive due to the number of glass elements within the lens.

Fish-eye or wide angle lens - (generally around 15mm) this is a common name for the opposite of a telephoto lens, whereby the lens itself is taking in light from a wide optical range (think instead of just focusing on something with our eyes in front of us, the angle of view increases to encompass things in our peripheral vision as well). these are often good for shooting things close up/not having much room to stand back from the subject, but will due to their convex nature, have a fair bit of distortion. just like noobvaks image above. some people like them, some people dont. and again, they can be very expensive.

UV Filter - A uv filter does exactly that, blocks UltraViolet light from entering the lens but ultimately does not alter the final product alot. however it is worth getting one to protect your lens at most times.

Positives # If the lens is dropped, the filter may well suffer scratches or breakage instead of the front lens element.
# One can clean the filter frequently without having to worry about damaging the lens coatings; a filter scratched by cleaning is much less expensive to replace than a lens.
# If there is blowing sand the filter may protect the lens from abrasion from sand.
Negatives
# Adding another element degrades image quality due to aberration and flare.

Polarising Filters - A polarizing filter, used both in color and black and white photography, filters out light polarized perpendicularly to the axis of the filter. This has two applications in photography: it reduces reflections from non-metallic surfaces, and can darken the sky. Essentially it works the same as if u had a pair of polarising sunglasses.