So in the Starter Set there is;
Base Shadow Brush - This is used to apply eyeshadow over the whole eyelid.
Deluxe Crease Brush - Designed for applying eyeshadow to the crease of your eye, which you do when you want to create some contour.
Accent Brush - This brush is small enough to be used for detailing and is described by Real Techniques as being suitable for spotlighting, highlighting, and smudging.
Pixel-point Eyeliner Brush - Although this says its an eyeliner brush, I don't think its firm enough to be able to precisely apply eyeliner, it could be used for applying highlighter inside the corner of your eye though.
Brow Brush - Despite this brush having the right shape, I think this is too thick to use as an brow brush, but it could be used for a thicker application of eyeshaow as an eyeliner.