SAN FRANCISCO -- Google is expanding its Android operating system to a wide range of connected products and seeking to make the experience identical and continual across wearable devices, cars and homes, the company stressed in the kickoff to its annual developers conference Wednesday.

Executives with the Mountain View Internet giant took turns showing off the next version of Android, the company's mobile operating system, along with smartwatches, in-car entertainment systems and televisions during the keynote address. The major message to consumers was that Android would present a single environment through multiple screens: Notifications cleared on a smartwatch would be cleared from the smartphone, for instance.

"We want to create a seamless experience across all these devices," Sundar Pichai, Google's senior vice president in charge of Android and Chrome, said in Wednesday's presentation.

Consistent interactions with a range of connected devices has become a major focus of consumer-facing tech companies, with Apple focusing on the concept, which it dubbed "Continuity," in its own developers conference keynote earlier this month. As devices far beyond personal computers and smartphones connect to the Internet, Silicon Valley tech companies are trying to control all aspects of the connected ecosystem and reduce pain points for consumers.

Google's opportunity in the space is massive: Pichai said Wednesday that Android recently surpassed 1 billion active users for the first time. To try to take advantage, the company offers Android Wear for smartwatches and other wearable gear, Android Auto for the car, and Android TV for the living room, along with new Chromebook functionality.

ANDROID WEAR

Google showed off three smartwatches from third-party manufacturers LG, Samsung and Motorola during the keynote address, in which every presenter was wearing a smartwatch. Executives stressed the interaction between watches and smartphones, with users able to bypass the lock screen on their phone while wearing the watch and apps for the phone automatically porting to the watch. The watches all include the Google Now voice-activation system, allowing users to set up a reminder or start music playing on a smartphone by verbally telling the watch to accomplish that task.

ANDROID AUTO

Much like Apple's entry into the automobile entertainment system with CarPlay, Google has worked with car manufacturers to have Android features useful while driving placed in in-dash stereos and screens by automobile manufacturers. Google Maps and third-party music and audio apps -- including podcast apps and services such as MLB's audio subscription -- will be included, and 25 car brands will ship Android auto in the near-future, with the first cars featuring the system being sold before the end of the year.

ANDROID TV

After Google's attempt at installing software into televisions before purchase, Google TV, failed to catch on and a set-top box-like device dubbed the Nexus Q and introduced at I/O two years ago never made it into stores, Google introduced the Chromecast, a streaming dongle for televisions that Google said Wednesday outsells all other streaming devices combined in many retail outlets. With Android TV, Google is combining all those efforts, putting Android TV into televisions as well as set-top and streaming boxes. while continuing to expand the capabilities of Chromecast.

With Android TV, Google search will allow for easy search of streaming-video options based on the user's subscriptions, and also allow Android video games to be played, all by using a smartphone, tablet or separate hardware as a remote control. The Chromecast will receive additional functionality, including the ability to fully mirror a device screen on a television set.

CHROMEBOOKS

Google's stripped-down laptops, which Pichai noted take up all the top 10 spots for Amazon's highest rated laptops, will receive more of an Android feel. Similar to Apple's "Continuity" offering, Chromebooks will interact with smartphones to ensure notifications appear on a user's Chromebook and allow for telephone calls and text messages to be answered on the laptop. As well, Android apps will be available on a Chromebook, similar to the interaction between smartphones and smartwatches.

OTHER ANNOUNCEMENTS

-- Google Fit: Like Apple's WWDC announcement of HealthKit, Google Fit is an API that allows developers to build apps focused on the "quantified self" movement, with a focus on wearable devices that include sensors to detect pulse, body temperature and other quantifiable bodily functions.

-- Native Office editing: Google Docs will allow users to edit Microsoft Office documents without converting them into different file formats.

-- Android One: A new version of Android built with the less affluent users in countries such as India in mind, Android One will be a Google-controlled operating system -- making updates easier -- that will be used on smartphones that cost less than $100 and have options popular in other countries.

-- Android L: The update from KitKat, the latest version of Android, will have a three-dimensional look and new animations.

-- Appurify: Google annoucned that it has acquired the San Francisco company, which allows mobile developers to test their products; Google backed Appurify with venture funding.

Staff writers Brandon Bailey and Troy Wolverton contributed to this report. Contact Jeremy C. Owens at 408-920-5876; follow him at Twitter.com/jowens510.