Ping is I think your internet connection. 1 means it really really fast while 900 is the lowest and really lagging, that or the other way around. I forgot but you are about the middle.

Ping time is a measure of latency, the time it takes for one packet of information to make a round trip from your computer to a second point and back again. It is measured in milliseconds, or thousandths of a second.

A ping time of 400ms means it takes 4/10ths of a second to communicate to another computer and receive a response.

For gaming, I can say from experience that is pretty bad. In Halo 2, such a player will almost surely be seen to "warp" instantly from location to location at times as the game makes bad predictions about where you will be next and then corrects itself.

At 700ms, the game is virtually unplayable even if the connection is stable.

At 250ms, the game is playable but you will be at a severe disadvantage in games using instant-hit weapons like shotguns and swords. As always, the host has zero latency and thus is able to use this weapons the best, but if another player who is not host has a latency of 100ms faces off against a player with a latency of 400ms using weapons like shotguns or swords, the 100ms player is going to almost always win, all other things being equal.

Check out the High Ping Guides for more info:

http://rampancy.net/hpbguides