jack-dorsey-demoTwitter creator Jack Dorsey has been in the middle of some big shifts at the top of the messaging service, and he addressed some of those changes today.

Dorsey, who was interviewed on-stage at the D9 conference in Rancho Palos Verdes, Calif., stepped down from his position as Twitter CEO back in 2008 and was replaced by his co-founder Ev Williams. It was reported that Williams and the board basically forced Dorsey to take a more passive role as chairman, leading to lingering bitterness.

But Dorsey offered a different narrative. The best founders are willing to put the company first, he said. So three years ago, Dorsey, Williams, and their third co-founder, Biz Stone, made the decision “as a team”.

“At that time it just made sense for Ev to take the CEO role,” Dorsey said. “And that was it.”

Whatever really happened back then, Williams has since stepped down in favor of current CEO Dick Costolo. And Dorsey is back in an active role, leading the company’s product efforts while continuing to run his new startup Square. He said his big aim is to continue to “take a lot of the friction out” — in other words, to make Twitter even easier to use. You can see that in Twitter’s recent announcement of photo-sharing capabilities on Twitter.com, which should make it even easier to share photos on the service. Yes, Twitter is already “very, very easy,” Dorsey said, but he added, “It’s just the beginning.”