The Higgs boson is the smallest detectable wave in the Higgs field. Interacting with the Higgs field causes articles to acquire inertial mass; without the Higgs field, no particle would have inertial mass. Some particles don't feel the Higgs field at all (photons) and so are massless; some feel it very lightly (neutrinos) and have little mass; ordinary particles feel it strongly.
In physics the current best understanding of the forces (excluding gravity) is called the Standard Model. The one remaining elementary particle in the Standard Model that hasn't been experimentally detected is - the Higgs boson.
Strong force (holds quarks together to form protons,neutrons)
Electromagnetism is the unification of electricity and magnetism, which were originally thought to be two different forces.
The next steps in physics would be:
Electroweak unification - electromagnetism and weak force unified into the "electroweak" force. The Higgs field explains why these two forces normally appear to be different. The discovery of the Higgs boson could be considered final verification for electroweak unification.