Quarks are elementary particles that are present in nearly everything in the world around us.  They make up hadrons, such as protons and neutrons. They always have a fractional electric charge , which means that, unlike protons or electrons which have charges of plus and minus 1, quarks' charges are positive and negative fractions. There are 6 different type of quarks, however they are usually referred to in pairs: up/down, charm/strange, and top/bottom. Like most other elementary particles, each quark also has a corresponding antipartice, called antiquarks. These particles have properties exactly opposite to their matching quark.