This means you can drag the skill to your Skill Bar located on the left side
SECTION 3 - Character Development Skills: To see what kind of Basic Skills you have, open the Skill tab on the bottom of the screen. Here, you can see what skills you already have (icons that are not grayed aion gold out) and what skills await you in the future (icons that are grayed out).
You can also read the description of each skill by moving your mouse over the icon. If there are skills that are not grayed out and also have MP consumption, this means you can drag the skill to your Skill Bar located on the left side of your screen.
For instance, if you have "sprint" available as a Basic Skill, and you drag it to number 1 on your Skill Bar, that means you can just press "1" and your character will use that skill. You may also drag potions to the Skill Bar to shortcut to them.
After level 10 you will be able to start training for your specific role as a Knight by speaking with [Grand Merchant] Kaishan in Moradon. Choosing your specialty will allow you to access your class specific skills (short-cut key "K"). (Note: Some skills have requirements for use).
Stats: Stats points are used to determine which armors, weapons and items you can equip and use.