Q What is it?
A The Higgs boson is a hypothesized elementary particle that, if confirmed, would provide the mechanism by which the other elementary particles in the universe have mass. Elementary particles are the smallest fundamental units of matter. It was once thought atoms were the smallest. Then there was the discovery of the atomic nucleus and its composition of two types of subatomic particles: protons and neutrons. Protons and neutrons are themselves made of elementary particles called quarks.
This discovery led to understanding that all matter is made up of quarks and electrons. Elementary particles can be divided into two classes -- fermions and bosons, which are defined by a quantum mechanical property known as "spin." Scientists believe that, at a quantum level, the forces that cause quarks and leptons to attract or repel each other are carried by bosons.
The Standard Model of elementary particle physics is a theory that explains how quarks and leptons interact in terms of three forces: The electromagnetic force, strong nuclear force and weak nuclear force. The Higgs boson is notable in that its interactions with the other particles are thought to give these particles their mass. It also is the only particle in the Standard Model that hasn't been directly observed.
Q What does it do?
A Scientists have theorized that the Higgs boson gives each type of particle its own mass. Its existence is needed to explain a number of the features of the Standard Model as it provides us with an understanding of why some particles have very large masses while others are quite light. Physicist Peter Higgs proposed what we now call the Higgs field and hypothesized that it spreads through the universe. All particles would acquire mass by interacting with this field. As is the case with the other interactions, at a quantum level this Higgs interaction predicts that we should be able to produce and detect the boson associated with it, or the Higgs boson. Mass of the particles would be the result of interaction with the Higgs field, and this interaction produces a Higgs boson. Because the boson is predicted by the field, finding the Higgs boson would be evidence that the Higgs field exists.
Q Why is it important?
A The Standard Model has been stood up to scientific challenge. The Higgs is the last missing component, leaving open the question about the theoretic formulation given to the masses ascribed to all of the particles in nature. If the Higgs boson is found, then the Standard Model will be further validated. If the Higgs boson is not found, then original problems with the Standard Model would need other explanations.
Q What's next?
A Further research will be needed to understand whether the discovery represents the particle in its simplest manifestation. It's possible there may not be just one Higgs, but a multiplicity of Higgs.