Comcast Corp. plans to introduce its X1 service in the Twin Cities on Tuesday, a system the cable company designed to keep up with changes in the way that people are accessing ­videos and watching TV.

Subscribers to Comcast’s X1 service will get a new set-top box to receive TV channels, download programs and connect to popular Internet services such as Facebook and Pandora. The box also has a digital recorder for capturing up to four programs that are being broadcast — or streamed — at once.

“X1 is a whole new operating platform that is easier to navigate,” said spokeswoman Mary Beth Schubert. “We have a fantastic content library complemented by social media and apps.”

The system is a response to challenges that Comcast, which is the dominant provider of cable services in the Twin Cities, faces from companies like Netflix Inc., Inc., and Apple Inc. that are providing TV programs and other entertainment through Internet streaming. As well, the X1 set-top box takes on some of the functions that were built into so-called “smart TVs” of electronics makers like Samsung Electronics Co. and Sony Corp. that access Internet services without going through a cable box.

In contrast to Netflix, Amazon’s Prime and Apple’s iTunes, Comcast delivers all the content over its cable network; an Internet connection isn’t technically required.

However, the company is limiting availability of X1 to customers of its “Triple Play” service, meaning those who subscribe to its cable TV, Internet and telephone offerings in one bundle. Those who sign up will have to pay a one-time $50 to $100 installation fee. There is no monthly charge for X1 beyond the price that people pay for the three services. Subscribers can also access the X1 content on their computers or mobile devices.

The X1 service already has been introduced in 15 other cities, and Comcast plans to offer it in all of its U.S. markets by the end of the year. Reviews in other cities have varied, with some praising the system’s ease of use while others complain about the required Triple Play subscription.

Schubert said the X1 service will eventually become available to other customers in the Twin Cities who don’t subscribe to the Triple Play package, but she offered no estimate of when that will be.

There is a limit to how much Internet content the X1 service provides. The service comes with TV screen apps for Facebook, the Pandora music service, weather reports, traffic updates, stock prices and sports scores. Requests for Web content travel through the Comcast cable TV system to a central location where Comcast retrieves the information from the Internet and returns it to the subscriber.

The X1 service in some ways resembles Netflix, the leading streaming service with about 30 million subscribers, but it also adds several more technology features.

Comcast allows the consumer to control the TV via an Apple iPhone or iPad equipped with a special app. And the set-top box responds to voice commands or gestures made with the mobile device. In addition, the X1 service allows simultaneous use of TV and Web information. In that way, a viewer can watch a baseball game with the sports scores app in a corner of the screen.

Comcast offers a library of 300,000 movies and TV shows; for licensing reasons, Netflix has a limited selection of streaming movies.

“The X1 was designed to transform the TV into an entirely new integrated entertainment experience,” Schubert said.

In a sign of how quickly the video delivery experience is changing, even as Comcast is in the midst of its national rollout of the X1 service, the company last month announced an upgrade called X2 that incorporates more features. Schubert said it wasn’t clear when the upgrade would roll out in the Twin Cities, however.

Some features were added to the X1 software at the time of the X2 announcement, including the ability to “fling” a video that’s being viewed on a smartphone or tablet onto the screen of a nearby TV.