1.

Battle Style icon:
Display of the battle style (class) of your chosen character.

2.

Mana Bar:
Display of character's existing MP (Mana Point).

3. Health Bar:
Display of character's existing HP (Health Point).
4. Character Status window:
Display of character's Name, current level.
5. NPC Status Bar:
Display of NPC or monsters' existing HP.
6. Mini-Map:
Shows your character's current location.
7. Chat Channels:
Clicking on this will display all the available chat channels.
8. Quick Slot:
Skills, actions, items and other various icons can be saved and used through the quick slot. Preferences can be placed in accordance used through F1~F12.
9. HotKey Slot:
The icons can be clicked to open specific options available in the game system.    
10. System Message Window:
Messages are displayed on this system message window.