Main Goal
Although some members joined Akatsuki to further their own goals, all are united in Akatsuki's ultimate goal of gaining world domination.Nagato has mentioned a three-step process to work their way towards this goal. First, they plan to obtain a large amount of money to support their organization.Second, they plan to set up a mercenary group loyal only to Akatsuki. To build their reputation, they plan to accept any mission below the usual cost and operate off of the excess funds earned in the first part of their plan.Because there haven't been any wars in some time, the established shinobi villages couldn't afford to charge such low prices, leading the smaller countries to hire Akatsuki over the more expensive shinobi villages. By using the tailed beasts, Akatsuki would start wars and then immediately quell them, solidifying their reputation and convincing every country to depend on them, thus cornering the market in shinobi labor.Without any business, the other shinobi villages would collapse due to the lack of funds.Finally, after Akatsuki is the only major force of shinobi in existence, they can easily conquer the other countries. Members do not automatically learn of the plan upon joining; Hidan didn't find out about it until he had been a member for quite some time.
The tailed beasts, nine gigantic demons of immense power, are the main focus of much of Akatsuki's efforts and screen time within the series. Each member is assigned to capture one of the nine beasts alive or, in most cases, the person that beast has been sealed into. Akatsuki has sealed seven of the nine beasts before the start of the Fourth Great Shinobi World War.