There were some questions in-game today about what companies do, so I thought I'd start up a quick forum thread on that topic. The short answer is that companies let players work together to claim territory, attack enemies, and generally work toward shared goals.

One way they do this is by providing tools for cooperation, a big one being shared vaults where company members can easily share their goods, and can in particular all craft from a shared set of ingredients. That can be a lot easier than always trading between characters or buying things at auction houses. Companies can control exactly how much access various member ranks have to these shared vaults.

Companies can also claim territory by placing holdings and outposts in wilderness hexes. To do this, they need to have enough Influence available. They gain Influence whenever their members perform actions that would count toward an achievement, like killing mobs or crafting items. This Influence is banked whenever a holding or outpost is placed or upgraded.

Influence can also be used to feud other companies, allowing them to try to capture each other's territory, or to attack each other without Reputation losses.

At the highest level, companies can own or join settlements. Companies that are attached to settlements, whether as owners or members, pass along that settlement's Support Level to all their members, allowing them to make full use of Feats that are only available from trainers of that level.

This blog post is a bit dated, but explains some of the basics about joining or creating a company.

Feel free to ask any follow-up questions about companies here, or to post any other information/links about companies that you think newer players might find useful.