The flat grind
A flat grind is pretty much what it sounds like: the blade is ground flat from the spine to the edge on both sides. In cross section, it would look like a triangle. Kershaw also puts an edge bevel on the blade, which forms the actual cutting edge.
The flat grind offers good cutting capabilities, strength, and depending on blade thickness, can also offer chopping abilities.
The slicer grind, designed by Rick Hinderer, is a type of flat grind used on some Kershaw knives made in collaboration with Rick. In this case, the blade grind tapers from spine to edge, but also from back of the blade to front. This enables to front of the blade to be an excellent slicer, while the thicker back part of the blade can be used for tougher push or draw cuts.