The W boson and Z boson are fundamental particles that mediate the weak nuclear force, one of the four fundamental forces in nature. They are responsible for processes like beta decay in atomic nuclei. The W boson comes in two varieties, W+ and W-, which carry electric charge, while the Z boson is neutral. Both bosons are heavy compared to other particles, with the W boson being about 80 times the mass of a proton and the Z boson about 91 times. They were discovered in the 1980s at the CERN laboratory, confirming key aspects of the Standard Model of particle physics.