A blender is an electrical kitchen device used used for blending, puréeing and emulsifying. There are two main types, countertop, and hand-held.
Hand beaters are used to beat a food item or food mixture, to both mix it and introduce air.
A pastry blender (aka pastry cutter) is a hand-held tool used both to cut solid fat into flour, and to blend it in thoroughly. It consists of a handle that has half-moon shaped wires attached to it at both ends.
A whisk is a kitchen tool using for blending, whipping, incorporating air and eliminating lumps in food. Most whisks are hand-powered, though some mechanical and electronic versions are available.