Our solarsytem. Whats the difference between a dwarf planet and a planet?

Ever since I was a little boy I have been reading about space. I learned the basics and more complicated theroies such as planet x, black holes and white holes. But once they anounced that pluto was a dwarf planet I thought THATS STUPDIST PIECE OF CRAP I HAVE EVER HEARD! I mean its still a planet! It says it's a dwarf "planet". On top of that its got a moon. It's not just pluto theres a dwarf planet in the asteroid belt between earth and mars. Theres also a good number beyond pluto. This whole thing about dwarf planets is nosense. I know its to do with m and volume etc. But it would be lot less complicated if we called them planets. On a sperate but similar note a couple of jupiters moons are planets to. That cant be possible a object orbiting a planet is a moon and by what I have read a moon cannot be a planet because it does not orbit the sun/star. It is the planet which orbits the moon while the moon orbits planet