Large Hadron Collider
"The Higgs boson is a "fundamental" particle; one of the basic building blocks of the Universe. It is also the last missing piece in the leading theory of particle physics - known as the Standard Model - which describes how particles and forces interact."
"The Higgs explains why other particles have mass. As the Universe cooled after the Big Bang, an invisible force known as the Higgs field formed together with its associated boson particle. "
Other stuff about the Large Hadron Collider
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle accelerator. It is expected to address some of the most fundamental questions of physics, advancing the understanding of the deepest laws of nature. The LHC lies in a tunnel 27 kilometres (17 mi) in circumference, as deep as 175 metres (574 ft) beneath the Franco-Swiss border near Geneva, Switzerland.