So here's some sort of a Higgs Boson for dummies thing by yours truly, hope it helps.
Imagine that everything in the world is made out of bricks, held together by glue. Now we're going to call the bricks fermions, and the glue bosons.
Fermions are "solid" particles, stuff like electrons. Bosons basically "carry forces", in a way. An example of a boson particle is a photon, which is a particle that doesn't really... occupy matter, so to say, but "carries light". That's what bosons do. Because they're cool like that, two (or more) bosons can occupy the exact same space, unlike fermions.
Higgs Boson - also called the God Particle - is a special type of boson. Its existence has actually been only tentatively proven in 2013, but has been theorised to exist for a long time before (by someone named Peter Higgs, unsurprisingly, though he wasn't alone, but he proposed the idea, so he got the name rights, I guess). It's special because it has no spin or charge, like - it's not anything on its own, it's just a helper to help other things become something. That's more or less the Higgs Boson. That's also why it's very unstable, because things that aren't anything have a tendency to become something, and why it took them so long to prove its existence.
Why is it important? What it does is helps shit stick together. Without the Higgs boson, our universe would be just a mess of particles speeding past each other, giving zero fucks. Higgs boson is the one that's like, hi there, you two, would you like to hold hands please? It allows particles to join together, to have mass, to become something instead of just nyooooooooooooooooooming by.
Wait, but how the fuck did they find it? Well, they kept smashing protons into each other at almost the speed of light for a very long time. Then one day they thought they saw it. Probably. Can't really be sure, since it disappears the moment you see it, pretty much. But they think they saw it. Probably.