whisk [hwisk] noun, verb
1. A tool with a straight handle that has several loops of wire on the opposite end, forming a bulb-like shape, which can be used to combine ingredients together.
2. The action of whisking, which aerates ingredients, such as eggs or cream.
Balloon whisks (shown in the rear right side of image) tend to be larger and quite rounded on the end, and French tapered whisks (center, top of image) have a more slender profile to fit into the corners of pots more easily. While traditional versions were all metal, you can find them in silicone (orange one in pic) with metal or wood handles or other more modern combinations. Some very newfangled styles have straight ends with balls attached (center) or are a series of loops on a flat plane, like a spatula with wires.
Bakepedia Tips
In our opinion, the classic whisk shapes are the most efficient, and we like whisks with very flexible wires. Very stiff wires are more difficult to use and do not produce the same results. One technique we use constantly is to use a whisk to combine dry ingredients instead of using a sifter. This aerates and combines the ingredients all at once, saving you time.