Are PCs or traditional laptops about to become as obsolete as the typewriter? Tablets are set to become the "preferred, primary device for millions of people around the world" by 2016, according to a new report from Forrester Research.

"There will still be lots of personal computers sold and in use - in fact our casual estimate is that there will be 2 billion PCs in use by 2016, despite growing tablet sales," said Frank Gillett, a Forrester analyst who focuses on predicting future scenarios, on his company's blog.

Tablet use will continue to grow in the next few years with at least 760 million tablets in use by 2016 said Gillet in a report titled, "Tablets Will Rule the Future Personal Computing Landscape." The tablet market will grow through the next five years with total sales rising from 56 million tablets sold in 2011 to 375 million in 2016.

"We forecast sales rising from 56 million in 2011 to 375 million in 2016," Gillett said. "Given that a majority of tablets will be retired within three years of purchase, we forecast that there will be 760 million tablets in use globally by 2016. One-third of these tablets will be purchased by businesses, and emerging markets will drive about 40 percent of sales."

Forrester isn't the only research firm expecting a global rise in tablet sales. Gartner is also forecasting tablet sales to reach 118.9 million units in 2012. Emerging markets will also drive tablet consumption as emerging markets are expected to account for 40% of all tablet sales in 2016.

Why are tablets replacing desktops and laptops as the computing device of choice even though they're not as powerful? It's because tablets are more convenient than desktops and laptops and have longer battery life than any PC. Tablets are also better for sharing in groups where users can just pass over a tablet with no distracting keyboards or the weight of a laptop to hinder users.

Tablets could also potentially kill of the laptop industry. "Our casual estimate is that there will be 2 billion PCs in use by 2016, despite growing tablet sales," says Gillett. "That's because tablets only partially cannibalize PCs. Eventually tablets will slow laptop sales but increase sales of desktop PCs. That's because many people, especially information workers, will still need conventional PCs for any intensely creative work at a desk that requires a large display or significant processing power."

And despite what Apple CEO Tim Cook may think about "hybrid" devices or devices that can turn into a laptop or tablet qualify as a tablet according to Gillet. Cook had said Tuesday in a conference call with analysts where he announced that iPad sales were up 1515 year-over-year in the second quarter, that Apple plans to continue to produce separate notebooks and tablets because hybrids would please no one.

"You can converge a toaster and a refrigerator, but you know those things are not going to be probably pleasing to the user," said Cook.

Apple's decision not to go into hybrids isn't likely to hurt the company as Apple's iPad is expected to account for 53% of the global tablet market base in 2016. Despite the growth of Google's Android software and the impeding release of Microsoft Corp. Windows 8 software that marries tablet and desktop use, Apple will remain king of the tablet hill for a few more years.