What Apple's Decade Old iPod Lawsuit Is All About

— -- Apple is prepared to defend itself today in a decade old class action lawsuit where one of the star witnesses is expected to be the technology giant's deceased co-founder, Steve Jobs.

The lawsuit focuses on Apple's early days of reshaping the music industry and whether it engaged in anti-competitive behavior involving its iPod music players.

Here's what you need to know about the case as it plays out in a federal courtroom in California:

At the Center of the Lawsuit

The plaintiffs, who are comprised of consumers and electronic retailers, claim that Apple engaged in anti-competitive behavior that had a widespread impact in the company's early days of reshaping the music industry when it launched its iTunes store in 2003.

The lawsuit claims Apple would only allow music bought from its iTunes store to work on the iPod. According to the plaintiffs, this required them to continue to purchase iPods in order to keep their music instead of competing cheaper music players.

Apple declined to comment on the ongoing litigation.

Herbert Hovenkamp, a professor at the University of Iowa and an expert in anti-trust law, told ABC News he expects Apple will argue it was trying to provide the best possible experience for its customers.

"They will very likely argue that the updated versions of their software were actual technological improvements to prevent hacking or prevent other kinds of interference," he said.

Hovenkamp said previous case law supports companies that make "an actual improvement" from antitrust violations, even if it makes some other products incompatible.

Steve Jobs' Role

There's a twist: Steve Jobs videotaped deposition will be a key piece of witness testimony in the case, despite the fact the Apple co-founder died three years ago.Legal wrangling has been going on in the case for nearly a decade, so Jobs was able to provide his side of the story, which could weigh heavily on the outcome.

Along with his videotaped testimony, Jobs' emails are expected to be presented as evidence in the case, according to the New York Times.

What's At Stake

If Apple loses the lawsuit, some consumers and retailers who purchased iPods between Sept. 12, 2006 and March 31, 2009 could be eligible for damages.

ABC News' Neal Karlinsky contributed to this report.