There are six types of quarks. The types are called flavours. The flavours are up (u), down (d), strange (s), charm (c), top (t), and bottom (b). Up, charm and top quarks have a charge of +, while down, strange and bottom quarks have a charge of -. Each quark has a matching antiquark. Antiquarks have a charge opposite to that of their quarks; meaning that up, charm and top antiquarks have a charge of - and down, strange and bottom antiquarks have a charge of +.