Which is a lower than the 20,000+ available on Steam international -- i.e. the version we all have sitting there minimised to our Windows system trays. Valve has been looking to bring Steam (officially) to China for a number of years now, and with Steam China up and running (you can check it out here) the initial offering is pretty small.
And kind of reminiscent to the early days of the platform. Steam China is also missing a number of community focused features too -- no discussions, or chat. As for the difference, well, Steam China only sells and features games that have received a license from the Chinese government -- a situation that sees only a limited number of pre-approved games released in any given year.
As of now the platform's debut is seemingly the home of Counter-Strike: Global Offensive, Dota 2, and not much else. Steam China is a different totally seperate thing either, as per this report by PC Gamer, Steam user reviews are here and the review systems are unified. Also, games purchased (that are actually available) on Steam international are accessible from within Steam China.
What's interesting is that Steam -- the for reals version -- is available to both Chinese developers and players. It's one of the reasons why the recently released Tale of Immortal, a Chinese RPG, is currently one of the most popular games on the platform. The benefit of Steam China is access to local servers, though with 53 games and no community features it doesn't exactly sound like Steam.