SAN FRANCISCO — Apple made its new smartwatch the star of its launch event Monday, but the company also showed off a new laptop and a HBO streaming service that will be exclusive on its devices.

Chief executive Tim Cook and technology vice president Kevin Lynch showed off the features available on the Apple Watch, including the ability to voice control the device with Siri, and displayed several apps created for the watch, including versions of Instagram and Uber, which will be available in a special store within the Apple App Store after an iOS operating system update available Monday.

Cook showed off the ability to receive and make calls on the smartwatch, as well as read and answer text messages and emails and make payments with Apple Pay. Health components will track and communicate a variety of body metrics.

The Apple Watch Sport will start at $349 and $399, depending on size; the Apple Watch will start at $549 and run as high as $1,099, depending on size and the band selected; and the Apple Watch Edition, the highest-end option made in gold, will start at $10,000 and be available only in some retail stores. Preorders will start April 10, and the devices will be available in Apple stores for viewing and ordering the same day. The watches will be available for immediate purchase on April 24 in the United States and some other countries.

Apple also on Monday showed off a new MacBook that Cook said “reinvents the notebook.”

The new MacBook is thinner than the MacBook Air and weighs only two pounds, Apple marketing executive Phil Schiller said, making it the thinnest and lightest laptop Apple has produced. It promises all-day battery life, with 9 hours of wireless Web use or 10 hours of video playbook, Schiller said.

Schiller also talked up a redesigned keyboard and trackpad, and disclosed that it will be the first MacBook without a fan and first available in the gold color that has been popular on iPhones and iPads. The computer will also have a single USB-C port that connects via USB, HDMI, VGA and DisplayPort as well as for charging with Apple’s Lightning connector.

The new technology does not come cheap, however: The new MacBooks will start at $1,299, and a faster version with more memory will sell for $1,599; they begin shipping April 10. The MacBook Air and MacBook Pro lines will also receive some slight upgrades, with new versions beginning to ship immediately.

The launch event began with the announcement that HBO’s streaming service will debut on Apple TV and devices exclusively next month. HBO chief executive Richard Plepler said the HBO Now service will debut in April for $14.99 a month, with the first month free for customers who sign up early.

Plepler said the streaming service will be available exclusively for a time on apps for Apple devices as well as Apple TV.

While Apple announced the watch in September along with new iPhones, analysts say the company had yet to make a persuasive case for why consumers should pay hundreds of dollars for a tiny computer tailored for the wrist.

“Smartphones already offer a convenient way to check the time, access the Web and apps, and increasingly pay for products,” Cathy Boyle, senior mobile analyst at eMarketer, said in an email Monday morning.