Meditation is used to passively level up your stats or skills and works both online and offline. Meditation points are earned in bulk early on by completing your starter tasks (access by pressing the J key), as well as many quests you will find throughout the world such as in dungeons. They can also be purchased with gold if you need more later and you have exhausted your early points. You will want to start your meditation as soon as you enter the game.
Meditation can be accessed through your Journal in the User Interface navigation bar.