Which lens is better? Sigma 70-300mm or Nikon 50-200mm?

What are the main differences between these 2 lenses what does some of the jargon mean?
1) Sigma 70-300mm DG Macro Lens for Nikon Digital SLR Cameras. £150

The Sigma lens is capable of macro photography with a maximum magnification of 1:2 at the 300mm focal length, providing you with crisp, clear close-ups. SLD (Special low dispersion) glass is used for superior correction of chromatic aberration and high image quality throughout the entire zoom range.

Focal length: 70-300mm.
Maximum aperture f/4-.
Minimum aperture f/5.6.
Manual and auto focus.
58mm filter.
Telephoto zoom lens.
Accessories included: lens caps and hood.
Weight: 545g.
Manufacturer's 3 year guarantee.

OR…

2) Nikon 55-200 DX Lens. £185

Enhance your Nikon camera experience with this 55-200 DX Lens. Featuring a silent wave motor for precision and a silent autofocus, this lens helps you deliver sharp, perfectly focused images for an impressively professional finish.

Model 55-200 DX

Nikon F lens mount.
Manual focus.
Accessories included: lens caps, hood and case.
Weight: 255g.
EAN/MPN/UPC/ISBN: 18208021567

Both from Argos http://www.argos.co.uk/static/Product/partNumber/5694198.htm

Nikon. Canon would be beter too.

Short answer. 70-300. I have both of them the 70-300 is better by far

There are some expensive, better quality 70-300mm lenses that would be better than the Nikon 55-200mm. The cheaper versions of 70-300mm are cheap from being not as good. If this is your budget, get the 55-200.

Nikon, my Sigma 18-125 is NOT sharp

I can tell you that the sigma is a decent entry level telephoto macro lens, I haven't used the nikon lens as I use canons but I would recommend the sigma as its quite a fun lens.

downside: its not the fastest when it comes to focusing, you need to get use to turning your macro on and off, while not using auto focus. Its a bit annoying at first.