SAN FRANCISCO -?Google on Tuesday introduced cloud storage service "Google Drive," one of the most important products the tech giant is expected to launch this year.

According to Google's official blog, starting Tuesday, users will be able to synchronize their files such as documents, photos, videos and songs across computing devices installed with Google Drive.

Since the files are stored in Internet servers, dubbed as "cloud," users will be able to access files anytime, anywhere through a web-connected computing device via their Google accounts.

The service is now available for PC, Mac as well as Android smartphones and tablets. But the version for Apple's iOS devices will come later.

Google offers first five gigabytes of storage per account for free and users can choose upgrades from 25 gigabytes for 2.49 US dollars per month to one terabyte a month for 49.99 dollars.

In the blog post, Sundar Pichai, the company's senior vice president, said Google Drive can stand from the already established cloud services for working seamlessly with users' overall Google experience, such as Google Docs, Google+, search and Gmail.

For instance, users can attach photos from Google Drive to their Google+ social network and attach files directly to emails in Gmail.

Cloud storage and collaboration is not new as Apple's iCloud, Microsoft's SkyDrive and Amazon's Cloud Drive, and services from cloud startups like Dropbox and Box have been in the market first.

Some analysts said Google might be late to the cloud game as millions of users have uploaded their files to other services. But others believed that from search, email to web browsers, Google's search engine, Gmail and Chrome all grow to grab a large market share as latecomers.