DSLR : Digital Single Lens Reflex

SLR stands for Single Lens Reflex,  single lens is in regards to what you see when you look through the viewfinder, the reflex part refers to the way it takes a picture. Which is a mirror that pops up for a split second just before the picture is taken.

Exposure: Exposure is the amount or lack of light on the subject of your picture. If there's too much light it can bleach the colours making everything too bright to see detail, too dark and everything has a shade of grey.

1): A DLSR would have bigger and better sensors for taking pictures compared to compact cameras.

2): A compact camera has the one lens that it uses and it can't be changed, with DSLRs you can use many different lens'. 

3): The quality of a DLSR is much better than a compact camera because of all the technology put into it.

4): Settings over ride on a DSLR make it superior to compact cameras, giving the user more control over the picture he's about to take.