hey Coolism...all details are there in this thread under the Advacned Guides.
http://forum.a3india.com/viewtopic.php?t=45
Also to give a small expample, currently there are 6 Grades of weapon starting from G1 to G6 for each class and Char.
For eg.: Sword Knight Weapons are:
Grade 1 - Lukihoo Sword
Grade 2 - Ester Sword
Grade 3 - Halpas Sword
Grade 4 - Remome Sword
Grade 5 - Agares Sword
Grade 6 - Lonove Sword
Each Grade starts from lvl 1 and can go upto lvl 10. This is called level upgradation. So for eg. a remome sword can start from lvl 1 and go upto lvl 10. To upgrade the lvl of your weapon use Upgrade jewel and to degarde it use degrade jewel. After lvl 5 you can use small master stone and after lvl 8 you can use large master stone.
U can also use crafting - details are there in the crafting guide under advacnced guides or you can visit this site:
http://a3.igamesasia.com.sg/itemcraftin ... g_home.htm
To upgrade the grade of ur weapon i.e G1 to G2 and so on...you can do so only by crafting. So you can change a Remome Sword to an Agares Sword...that is called Grade upgradation.