13 is the screen size.
The XPS has been out a VERY long time. A friend bought his XPS at the same time I bought a Macbook at the end of 2008. He was still using it without upgrade or rebuilds in 2015 and 2016 after I'd replaced the Macbook as my main computer. Current XPS machines are a lot nicer than the early versions, which were very light but 'plastic-fantastic' for the era. A few days back I used my old XPS again, and it's just a really nice machine: great keyboard and trackpad, super screen (QHD 15") and feels comfy on my lap. Wish I'd spent the extra and bought another 15.
Anyway, deal:
www.hotukdeals.com