How do tiles and samples work when rendering?

Hi, i just had a general question. In the render options you have the option to change samples and tiles; what are these two things exactly and how do they work?


Greg Zaal presents an add-on that automates the selection of proper tile sizes for your renders.


Ok; thanks man.

I wanted to know how they “work.” Whats the difference if I render by x:16 y:16 or x:64 y:64?