Nvidia Already Released the 800 Series Mobile Graphics Prior to the Desktop Graphics, for some Odd Reason They refreshed the 700 Series on the mobile (Laptops) with the GTX 800 series (naming Scheme) without releasing the Desktop 800 series so they decided to say fuck it and they released 900 series Desktop parts and then later on plan to release 900 series on laptops. so that the "Numbers" or Titles were in sync with each other. to explain it more thoroughly while the 700 series (GTX 770, 780, 780ti) were already released on the desktop space, the GTX 800 series were already out on the Laptops. but there 800 Series didn't exist on the Desktop Space, so they replaced the laptop 800 series on the laptop with the 900 series and then skipped 800 naming scheme on the desktop. so that both the laptop and desktops both had the naming GTX 9XX. (XX being the 60s, 70, and 80's parts.) and the GTX 900 M-Series being for the Laptops.
600/700/800 series cards and mobile are based on the Kepler architecture.
900 series are the new Maxwell architecture.
1000/1100 will be Pascal architecture.
nVidia is trying to push ahead quickly. Kepler was getting long in the tooth and needed to be retired before AMD floods the market with lower cost cards with the same performance.
Video cards have either two different cycles. Either a radical architecture every 18-20 months or two different series based off the same architecture, typically only die shrink difference, spaced 12-14 months apart. Kepler lasted 2 and half generations and therefore screwed the naming scheme.