End mills are versatile cutting tools used in milling operations. They come in various types, such as square end mills, ball nose end mills, and corner radius end mills, each designed for specific applications. End mills feature different characteristics, including flute count, helix angle, and coatings, affecting factors like chip removal, surface finish, and tool life. Understanding these aspects helps optimize end mill selection for efficient and precise machining processes in industries like manufacturing, metalworking, and woodworking.