Titles and Factions

Among other information, the Hero panel includes a list of your character's titles and faction. You can open that panel with the "H" key, and then click on the Title (or Faction) tab for more information. Once you've earned a title, you can select it in the Title menu so that appears under your character's name.


Titles

Performing certain heroic deeds (and some not-so-heroic-but-still-impressive deeds) can earn your character special titles. Some titles have multiple levels of achievement, defined by the number of times you complete a certain task. Here's a few examples from the cooperative part of the game:
To earn an Exploration title, you must explore a certain portion of the World Map. The first one, Explorer, requires you to explore 60% of the map in a campaign.
For a Skill Hunter title, you must capture a certain number of elite skills. The first one requires you to capture 90 elite skills.
For a Protector title, you must complete all the missions in a campaign, along with bonus objectives. For example, Protector of Tyria requires you to complete all 25 missions in Prophecies, along with their bonus objectives.
For a Treasure Hunter title, you must open a certain number of chests, each requiring a key that costs at least 600 gold. The first one requires you to open 100 chests of that kind.
For a Wisdom Title, you must identify a certain number of rare items. The first one, Seeker of Wisdom, requires you to identify 100 rare items.


PvP Titles

Competitive areas of the game have their own PvP Titles. Examples include:
The Champion title is earned for winning "guild-versus-guild" battles against guilds with a rating of 1200 or higher. The first one requires you to win 25 GvG matches of this type.
The Gladiator title is available to players who have a winning streak in the Random Arena. The first one requires you to have a 25 consecutive wins in that arena.


Faction

Faction is a reward you receive for achievements in player-versus-player conflicts and special cooperative PvE missions or repeatable quests.
Guild Wars Prophecies introduced Balthazar's faction, a reward for competitive PvP.
Guild Wars Factions introduced Luxon and Kurzick faction, a reward for competing in a PvP conflict or PvE challenge at the heart of that campaign. http://www.guildwars.com/gameplay/exploring/titlesandfactions.php