Adventure Journal (press F4 to open or click the feather icon in the game menu) contains deep information about your character's achievements in the game. Those may be in categories such as Item, Monster, Crafting, Maps and Contents. While exploring the world you will expand your Adventure Journal and information about your travels will be recorded in a suitable category. New records will gain you a certain number of points which will be added to your character's score. Based on the score, your character's achievements can be compared to other characters on your server.
Expanding your Adventure Journal also brings you various rewards. By gaining points in various categories you will be rewarded some silver. Finishing monster and map related achievements will also reward you with EXP cards. To receive this rewards, you must visit some of the Wings of Vibora NPCs in cities.
Adventure Journal - Item
When a completely new item is added to your Inventory it will be added to your Item tab in the Adventure Journal as well. You will gain 10 points to your score when finding new item. For equipment and gems, you will gain 10 times the number of stars of the item.
In this tab you can also see what monster does the item drops from or when it has been added to your journal.
Adventure Journal - Monster
After you "last hit" a monster it will be added to your Adventure Journal. As for now, there are few known bugs in this tab. However you still can see what's the highest damage you've dealt to a certain monster, how many monster of given type you've killed or even detailed information about the monster and kill/damage ranking for a specific monster by hovering the monster's image.
Adventure Journal - Crafting
When you gain a recipe for an item it will be added to your journal. By crafting a new item you will gain 10 points to your score. You can check here which needed ingredients you already have too.
Adventure Journal - Maps
While moving across the zones you will reveal the area around you. You can see here the percentage of revealed area of certain zones.
Adventure Journal - Contents
You can see information about your achievements in other contents of the game here.