T he much-anticipated Marriott Marquis Washington, D.C. opened Thursday after more than 20 years of planning.

District officials are hoping the 1,175-room convention center hotel will bring more group bookings and conferences to the area. But Marriott executives say there is much more to the 1.1 million square-foot building than meets the eye.

Here are four things that make Washington’s newest — and largest — hotel different:

1. A new kind of room service

Room service is dead, says Daniel A. Nadeau, the hotel’s general manager.

Just consider the statistics: Among Marriott customers, about 40 percent eat in their rooms — but only 6 percent eat food purchased from the hotel.

“Most [guests] are ordering out or bringing food back to their rooms,” Nadeau said. “People are less and less taking advantage of room service as it exists today.”

Enter Dining Your Way, which Nadeau says is a hipper, more practical alternative to room service. Instead of rolling tables and plate covers, the 24-hour service takes a page out of the popularity of delivery sites such as Seamless.com.

Hotel guests can place orders in advance and have the option of picking up their food if they don’t want it brought to their room.

“It’s a dramatic shift in how we do room service,” Nadeau said. “We’ll get food to customers much faster.”

“And no more signing a check,” he added. “We’ll just have a receipt stapled to the side of the bag.”

2.Amenities via mobile app

Need new towels or want late check-out? Now there’s an app for that.

In addition to checking in and out of their rooms using the company’s mobile app, guests at the Marriott Marquis Washington, D.C. can request everything from more blankets to wake-up calls with the push of a button. This is the first Marriott hotel in the Washington area to provide the amenities-via-app service, which the company began rolling out last year.

“This is a huge benefit to our customers who are arriving to the hotel at all different times from different locations,” Nadeau said.

3.An around-the-clock lounge

This, said William Wallace, is what luxury living looks like: comfortable couches, flat-screen TVs, an outdoor patio and around-the-clock booze.

The M Club is a concierge lounge on steroids, said Wallace, director of sales and marketing for the hotel. The room, located on the 12th floor of the hotel, offers a full breakfast, nightly hors d’oeuvres and a 24-hour bar for gold and platinum Marriott Rewards members. Guests can also pay a fee to access the lounge.

“If you get in at 2 a.m. from Amsterdam or Tokyo, or you can’t sleep, it’s a good place to come,” Wallace said. “You could spend the whole day here.”

4.A nod to Hot Shoppes

Bethesda-based Marriott International got its start in 1927 as Hot Shoppes, a root beer stand on 14th Street and Park Road NW. The family diner lasted for more than 70 years until the last-standing Hot Shoppes, in Marlow Heights, Md., closed in 1999.

Marriott’s newest venture — and its 4,000th property — pays homage to its roots with Anthem, a modern-day diner with nine replica stools from Hot Shoppes.

The restaurant will also serve longtime favorites such as Mighty Mo hamburgers and ham-and-cheese Teen Twists.