Here's how I broke it down for myself, and maybe it will help you too.
Particle Physics tries to explain what makes up matter. They look at the tiniest particles to give them explanation of how the universe was built and even how galaxies stay together. These physicists study many things, but they are very interested in the properties of subatomic particles, or bosons.
In 1964, three scientists, one named Peter Higgs, wrote papers postulating that there is another boson out there, very different from the rest. It was named the Higgs Boson, with the controversial nickname, The God Particle. Scientists have been looking for evidence of this particle for decades now.
Here are a couple of videos with a little more explanation:
From the Washington Post article: "After the Higgs Boson discovery, what's next for physicists?"
“At the beginning I had no idea a discovery would be made in my lifetime,” Higgs, 83, said at a press conference in the Old College at the University of Edinburgh, where he worked from 1960 until his retirement in 1996. “It’s very nice to be right sometimes.”http://public.web.cern.ch/public/en/lhc/lhc-en.htmlScience is always changing, always checking itself, always looking for explanations. And sometimes, when they make a discovery, it opens all kinds of nearby doors that before seemed shut. So this week is a big deal - we might be a little bit closer to finding out more about the mysteries of the Universe.
If you want to read more:
The Higgs Boson Made Simple at The Cosmic Log at MSNBC (lots of videos at this site)
Physicists Find Elusive Particle Seen as Key To Universe at the NY Times
"What Exactly IS the Higgs Boson?" in How Stuff Works