Gearscore is an addon that assigns a numerical value to every item you equip. It bases the value off of the rarity of the item, i.e. green, blue or purple, and the ilevel.
The sum of all of your individual items makes up your "Gearscore" and if you have the addon installed, it will show you someone's gearscore when you target them and also when you see someone in the lfg tool (going off the last GS they had when you were close enough to inspect them).
For example, If you're a fresh 80 with mixed quest greens and blues, you might have a GS of around 2800. After you've run some normals and heroics and are mostly in blues and purples, you might be around 3800 or so. To crack 4000, you'll need to be in almost all 5 man heroic purples.
Before the patch a lot of people on my server wanted a GS of over 4400 for the "harder" raids like 10/25 ToC because you could only do that by getting gear from heroic ToC's (which have a higher ilevel - 219, compared to normal heroic items which are ilevel 200), badge turn in's, and raiding. Basically, it was a method to try to insure that you had invested some time on your charactor and had some idea what you were doing.
Before 3.3, a gearscore of 4900+ pretty much meant you were a hardcore raider (or were very lucky with pug drops). Now in 3.3, with badges falling like rain from 5 mans, it's not hard for anyone to get a respectable gearscore in a relatively short period of time and thus GS is becoming less relavent.
The sum of all of your individual items makes up your "Gearscore" and if you have the addon installed, it will show you someone's gearscore when you target them and also when you see someone in the lfg tool (going off the last GS they had when you were close enough to inspect them).
For example, If you're a fresh 80 with mixed quest greens and blues, you might have a GS of around 2800. After you've run some normals and heroics and are mostly in blues and purples, you might be around 3800 or so. To crack 4000, you'll need to be in almost all 5 man heroic purples.
Before the patch a lot of people on my server wanted a GS of over 4400 for the "harder" raids like 10/25 ToC because you could only do that by getting gear from heroic ToC's (which have a higher ilevel - 219, compared to normal heroic items which are ilevel 200), badge turn in's, and raiding. Basically, it was a method to try to insure that you had invested some time on your charactor and had some idea what you were doing.
Before 3.3, a gearscore of 4900+ pretty much meant you were a hardcore raider (or were very lucky with pug drops). Now in 3.3, with badges falling like rain from 5 mans, it's not hard for anyone to get a respectable gearscore in a relatively short period of time and thus GS is becoming less relavent.