Which lens is better for nikon d90?

I'm having the (AF-S DX NIKKOR 18-105mm f/3.5-5.6G ED VR (5.8x. Now and I'm thinking of upgrading my D90, so Which of these is better:
1- AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II (11.1x) Or:
2- AF-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR (5.5x)
and what's the meaning of 00-000mm and (0.0x)?

"Better" depends on your needs. The 18-200 is a good all around lens covering wide angle to moderate zoom. On the short end (18mm) it is the same as your current lens. On the long end (200mm), you will get two time more magnification than your current lens. Is this worth it to you?

The 55-300 gives you more zoom and slightly better aperture. At 300mm, it's gives about 3 times more magnification than your current lens. This is good for shooting wild animals and other things requiring a moderate telephoto lens.

If you really need a long lens, consider the Sigma 150-500mm or the 50-500mm lens. They are big and heavy, but it is great for shooting wildlife.

The 18-200 means it has a focal length from 18mm to 200mm, 18mm being zoomed out the most, 200mm zoomed in the most. The 11.1x is 200 divided by 18, or the zoom range. The 11.1x designation is generally not used to specify a zoom lens for a DSLR.