As companies battle for dominance, it's the mobile world they want to conquer.
It takes only the lightest excavation of 2012's tech headlines to uncover the overriding theme. To no one's surprise, it was mobile, again.
As in 2011 and 2010, the quest to own the "post-PC" future was the common denominator in the sector's largest acquisitions, lawsuits, investments and products this year.
But if the year in tech wasn't exactly distinguished by theme, it was perhaps characterized by magnitude. The transition to the mobile and multi-screen world is rapidly picking up speed, as more of us use more of these devices more often.
Technical advances both large and small continue to push the limits of smartphones and tablets, making them more useful, helpful, personalized and addictive. Among these: improved network connections, faster chips, better batteries, higher resolution displays, more intuitive interfaces and more powerful software.
In particular, we've seen steady advances in the "cloud," as online storage and services allow us to easily pick up wherever we left off in a task, website, book or movie at any location, at any time, on any device.
"As we sit here in 2012, digital is embedded into the fiber of every aspect of our culture and our personal lives," said Tim Bajarin, president of the consulting firm Creative Strategies in the San Francisco Bay area.
Framingham, Mass., research firm IDC published a chart this month that neatly paints the dimensions of this shift.
The stacks of flat and rising bars show shipments of laptops and desktops fell an estimated 2.6 percent from 2011 to 2012, while the number of smartphones and tablets leaped by nearly half.
"Everybody used to be able to count on the PC industry growing 10 percent a year," said Carl Howe, an analyst with the Boston-based Yankee Group. "No more. It's disrupting that whole ecosystem in a big way."
Which is another way of saying that there's a fierce battle under way to stake claims in the mobile world.
It's why software makers are diving deeper into hardware, with Google delivering the Nexus 7 tablet and closing on its purchase of Motorola Mobility this year. Microsoft went over the heads of its hardware partners to deliver its own tablet as well, the Surface, along with an overdue upgrade of its flagship Windows software tailored for touch-screen devices.
Both those products earned mixed reviews, at best, underscoring the challenges Microsoft faces as it attempts to navigate the mobile landscape.
Apple, which has done more than any single company to drive this trend, sought to retain its dominance with the launch of the iPhone 5 and the iPad Mini, among other product upgrades this year.
Social giant Facebook had its own rocky relationship with mobile.
One of the reddest flags in its initial public offering filing was the fact that huge portions of its users were now accessing the social service over smartphones, where it had yet to prove it could make much money from ads.
Largely to improve its mobile standing, Facebook overhauled its mobile apps this year and snagged Instagram, the popular photo-sharing service, in a deal that ended up costing north of $700 million.
It would be simplistic to argue that we'll be doing all of our computing on phones and tablets anytime soon, or perhaps ever. Heavier productivity tasks are still much easier to pull off on standard laptops and desktops.
To the degree that even 5 percent or 10 percent of what users need to do requires an actual PC, there will be demand for those devices. In fact, IDC sees PC sales growing slightly next year, in part because of the new cycle of products driven by the release of the latest Windows.
But on the whole, the gap is expected to grow between PCs and mobile devices in the years ahead. And that fundamental shift will continue to create opportunities and challenges along every link of the supply chain, as well as new and better products for consumers.