The elementary particle discovered in 2012 that is associated with giving mass to other particles is the Higgs boson. It is the observable quantum excitation of the Higgs field, an invisible field thought to fill all space.
In 1964, physicists including Peter Higgs and François Englert proposed the mechanism that explains how elementary particles acquire rest mass through interactions with this field. On 4 July 2012, the ATLAS and CMS experiments at CERN's Large Hadron Collider announced evidence for a new particle with the expected properties. Higgs and Englert received the 2013 Nobel Prize in Physics.
The popular phrase “God particle” can mislead. The Higgs boson itself does not simply give every object all its mass. The Higgs field contributes to the masses of elementary particles such as electrons and quarks, while most of the mass of protons and neutrons comes from energy associated with quark motion and the strong force.
The Higgs boson is a boson, not a fermion, and it is electrically neutral. Its discovery completed a major missing piece of the Standard Model.