Walt Disney World Parks & Resorts Senior Vice President Jim MacPhee talks about the rollout of "next-generation" park experiences, during a preview tour of MyMagic+, at the Magic Kingdom, Tuesday, March 18, 2014.  (Joe Burbank/Orlando Sentinel)

Disney's "MagicBands" are more than the latest theme-park fashion statement. The colorful wristbands are at the heart of the company's billion-dollar MyMagic+ technology system, which allows visitors to make reservations, along with other benefits.

Disney World offered a briefing Tuesday as the company rolled out the MagicBands to annual passholders. Here's what park visitors need to know.

What's so magic about MagicBands?

The bands contain a microchip that allows them to be used as admission tickets. Simply tap a MagicBand against a reader at the front gate and walk in. They also keep track of the attractions for which a guest has made reservations — in a system called FastPass+ — via the My Disney Experience website or app. For Disney World hotel guests, they work as room keys and charge cards, too.

Who will get them?

Visitors staying in Disney hotels have been sporting MagicBands for months. Now, the testing phase is expanding to include Disney World's annual passholders, who are receiving email invitations. Passholders order the bands, which are mailed to their homes. MagicBands cannot be picked up at the theme parks.

Daily guests will be using MyMagic+ soon, said Jim MacPhee, senior vice president of Walt Disney World Parks. They will have the option to buy a MagicBand for about $15.

There is no charge for FastPass+ reservations.

Do they really reduce the wait time for rides?

Guests with FastPass+ use an attraction's designated entrance at their appointed time, which should make for short waits. Annual passholders will be limited to three FastPass+ uses per day, however, and all three must all be for the same theme park.

Kyle Newton, an annual passholder from Tampa, said he liked the MagicBand, but said he is frustrated by some limitations, especially the inability to have FastPass+ appointments in different parks on the same day.

"Maybe it's because we had mastered the old system" that allowed park-hopping, said Newton. "I'm not sold on that yet."

Those restrictions may change as Disney gains experience with MagicBands, MacPhee said.

"We focused in on three — as an opportunity to get three at once — as our starting point. We're already learning a lot, and we make adjustments along the way based on that feedback."

Parkgoers also can make FastPass+ reservations upon arriving at the parks each day.

What else can they be used for?

Visitors can make reservations for select character meet-and-greets or save a spot on a parade route.

"Rather than sit on the curb waiting a long time for the parade, you can just show up immediately before it arrives," MacPhee said.

MagicBands can also keep track of pictures taken by Disney's in-park photographers and can activate the Sorcerers of the Magic Kingdom, an interactive game played at the park.

Hotel guests are testing a FastPass+ lunchtime offering for the popular Be Our Guest restaurant at Magic Kingdom. Users can order their food in advance, bypass lines altogether and go directly to a table. The MagicBand chip tells servers where to deliver the meals.