To understand the tricky territory that separates website from app, consider the example of Comcast’s Xfinity TV.

When subscribers who want to watch TV online visit the cable operator’s XfinityTV.com on their tablets, they may notice the website now has the same finger-swiping navigation as its app.

This recent upgrade may be a distinction without a difference to the consumer eye but could herald a significant shift for rights holders.

That’s because they’ve licensed more than 200,000 TV episodes and movies to the Comcast site. But only about 9,000 titles have been licensed to the Xfinity TV app — a limit that may be

irrelevant when a Comcast sub accesses the website from a tablet in the future. Though the MSO currently keeps the full range of video on XfinityTV.com off limits when accessed on tablets, it may not remain that way forever, according to Matt Strauss, senior VP and g.m. of Comcast Interactive Media.

“The issue with the iPad is, is it a PC or a wireless device?” said Strauss. “The answer may be different depending on if you’re streaming content from a browser or an app. That blurriness is causing some confusion in the world of rights and will likely continue as websites become more optimized for mobile consumption.”

That may not sit well with programmers who want to be paid for access to their content via an app, which could lead to their next legal skirmish with video distributors looking to take TV content outside TV. Viacom and Time Warner Cable are already enmeshed in a lawsuit over the MSO’s transmission of its linear channels to iPads.

But while that lawsuit hinges on the questionable difference between a TV set and a tablet, this potential new debate asks what’s the difference between a website and an app when viewed on a tablet.

Many content companies and distributors are just beginning to grapple with this issue as they negotiate affiliate deals like the one Comcast sealed Wednesday with Disney.

Many of these pacts were first made when a website was narrowly defined as a browser-based experience confined to a computer while wireless rights were first conceived in the pre-app world.

Some programmers have granted rights to far more content to websites than they have for wireless, which may be meaningless once distributors begin to make websites the distribution point for wireless devices in addition to apps.

That could happen thanks to the advent of HTML5, the relatively new coding language whose usage is increasing because it can give a website the sophistication of an app. In success, HTML5 threatens to supplant apps, though the consensus is they will at least coexist in the short term.

There are plenty of arguments on both sides of the HTML5 vs. app debate. But the primary benefit to the former is that while apps require individual maintenance on each of the increasing number of platforms on which they operate, HTML5 provides a simpler solution.

“When you think about delivering video content through a a smartphone or a connected TV or game consoles, a lot of effort goes into maintaining that in today’s environment,” said Steve Necessary, VP of video strategy at Cox Communications. “If those capabilities were done in HTML5, it gets a lot closer to writing it once and deploying across multiple platforms.”

None of the content companies contacted to discuss how HTML5 figured into their distribution strategies were willing to discuss it on the record.

Some content companies who own all their content could attempt to wrangle a new revenue stream if their answer to the confusion is granting a new right to distributors. Other companies may not even be able to attempt to extract new fees until they’ve settled up with the studios from which they license that content.

“Some content providers are more than happy to say as long as the customer is paying, we’ll work with you to authenticate access to that content on multiple devices at no charge, just continue to protect the content,” Necessary said. “Others don’t take that position. In all cases, there’s a conversation.”

Comcast can’t just flip the switch on streaming all the content on its website from tablets tomorrow. The company is working through the technical hurdles to ensure that the same DRM that can be imposed in an app environment can be applied to HTML5-empowered websites.

From there, Comcast could even reconfigure the Xfinity app to direct users to a website without them even realizing they’ve left the iOs or Android environments.

Comcast hasn’t decided what it will do when it becomes technically feasible to make all that content available on the website via tablet, according to Strauss.

The Xfinity TV app was downloaded 4 million times in 2011 while the website is closing in on 8 million unique visitors per month.