Apple's iOS 11.4 rolls out today, and it brings a big update to HomePods: AirPlay 2 with multi-room audio. The update allows the HomePod and Apple TV (the two Apple devices that currently support AirPlay 2), as well as forthcoming third-party AirPlay 2 devices, to play the same audio throughout your home or only in select areas of your home.

All AirPlay 2 devices can be controlled using an iOS device, HomePod, Apple TV, or by asking Siri. Users can say, "Hey Siri, play classical in the living room," and the appropriate audio will play through the AirPlay 2-compatible speakers, but only in the living room. Essentially, the new setup makes it easier for users to play in-sync audio through all (or only some) of the speakers in their home.

Manufacturers that pledged to support AirPlay 2 include Bang & Olufsen, Bose, Bowers & Wilkins, Marshall, Pioneer, and Sonos. AirPlay 2 devices will now show up in the Apple Home app, since AirPlay 2 integrates with HomeKit. In addition to using Siri or individual apps to control speaker selection and music playback, all AirPlay 2 devices available in a home will show up in iOS' Control Center.

AirPlay 2 makes HomePod a more competitive smart speaker, and a more user-friendly one. For those with multiple HomePods across their home, they will now be able to fill their entire home with in-sync audio through multiple speakers or only in select areas like a bedroom, office, or patio. Airplay 2 also helps HomePod get along with other manufacturers' speakers (like those from Sonos) to play music through all the speakers in a home at the same time.

The AirPlay 2 update also allows two HomePods to connect via stereo pairing. That means one HomePod in a room plays the right-channel content while the second HomePod plays the left-channel content at the same time. Stereo pairing, combined with HomePod's spacial awareness feature, means that the devices can fill a room with sound that has more depth, balance, and power than before.

iOS 11.4 also brings Messages in iCloud to the operating system, a feature that has been in the works since iOS 11 was first introduced last year. Messages in iCloud stores all iMessages in Apple's cloud storage rather than on each individual device. Previously, all devices signed in to a user's iCloud account received iMessages. Users who saved all of their iMessage conversations may have found their local storage space taken up by large iMessage logs since all that information saved to individual devices.

Messages in iCloud moves all those messages—including attachments and photos shared in those messages—from Apple devices to iCloud. That frees up storage space for other things like music, photos, and more. While this is good for device-storage optimization, it may not be good for users who don't have a lot of iCloud storage to spare. Messages in iCloud also makes it easier to delete message information—delete a message, photo, or other attachment from one device and it automatically disappears from all of your other iCloud-connected devices.

You can check out the full release notes for iOS 11.4 at Apple's website. Users can download iOS 11.4 by going into the Settings app and navigating to Software update under the General tab. HomePod users can update device software in Apple's Home app.

Apple additionally released tvOS 11.4 to add AirPlay 2 to supported Apple TV models. Today also saw the release of watchOS 4.3.1, which Apple says improves performance on the Apple Watch.