Yesterday, physicists announced that they had found its signature in the data produced by the Large Hadron Collider. First proposed by Edinburgh University physicist Peter Higgs in 1964, the elusive boson is the final particle predicted by the Standard Model of particle physics, and is what provides matter with mass.
While the model describes the action of the electromagnetic, weak and strong nuclear forces and their role as traffic cop to the known subatomic particles, which now includes the Higgs, a theory of physical universe will only be complete by accounting for gravity. String theory, for example, proposes one unified description of the universe.
Using some sand, foam and white board, Guardian science correspondent Ian Sample explains what the particle is and why it's important in this video.
PHD Comics also does a nice job in the video embedded here.
You, of course, can get a first hand explanation at IdeaFestival 2012 from Lisa Randall. Make plans to be there!