It’s not often a new type of computer has a real impact on the world of IT. Whatever happened to tablet computers with rotatable screens, built-in keyboards and a stylus for writing on the screen? How about the ultra-mobile PC – remember those? Oh – and anyone remember the Amstrad E-m@iler? That’s one innovation Alan Sugar never mentions on The Apprentice.

However, every once in a while, something comes along that does change things. Last week, a piece of news emerged that suggests one new type of computer is starting to have a real impact – both at home and in the workplace.

Apple’s runaway sales success

Apple’s iPad is already supremely dominant in the UK tablet computer market, accounting for nearly three-quarters of all tablet sales. And it’s now emerged that Apple is selling more iPads than Dell is selling laptop computers.

Given that Dell is one of the world’s biggest computer manufacturers (the company claims it ships over 10,000 systems a day), that’s an impressive statistic. And it gives some clue as to the long-term effect the iPad – plus other tablet computers – could have on the sort of computers we use and how we use them.

Increasingly, it looks as if people are embracing the iPad enthusiastically, swapping full-spec laptops for the thin, light, super-easy-to-use Apple gadget. And who can blame them? No long waits to boot up, no fiddly trackpads or buttons … just a simple touchscreen that anyone can use, plus thousands of apps.

The next year or so could see tablet computers (and the iPad in particular) becoming established as the mobile computing tool of choice. Unless you need a full-size keyboard, it’s getting harder to see what benefits are offered by traditional laptops for typical on-the-move tasks like checking email or reviewing documents.

Netbooks are dying

Just ask the companies who make netbooks, the small, cheap, low-powered laptops that were predicted to reshape the PC industry. Things don’t look great for them: netbook sales have slumped 40%, and blame is being laid at the door of the iPad.

The argument stands up: to many people, netbooks seem like compromised laptops. If you can’t type comfortably on the keyboard and you find yourself squinting to see the small screen, it’s clear a tablet computer might be a better option.

What’s more, tablet computers like the iPad are developing at an impressive rate. Will the combination of more impressive hardware and more versatile apps persuade more people to swap their netbook or laptop for a tablet?

Laptop manufacturers certainly are worried. You can tell, because the main players in the market are rushing to release ultrabooks, another new kind of computer which is a bit like a netbook but thinner, more powerful and (of course) more expensive.

These sleek machines have enough punch to replace your desktop computer, but are designed to start up instantly and be small enough to take anywhere. They look great, they perform well and – although they can be expensive – they’re likely to find themselves a spot in the market.

Is it all Apple’s doing?

Long term, no matter which way things go there’s one IT firm that looks particularly well-placed to clean up. That company is Apple: because not only has it secured a huge slice of the tablet computer market, but it also makes the MacBook Air. This is the computer that pretty much defined what an ultrabook should be, and still represents the standard other manufacturers aspire to.

Never mind the ultrabook vs. netbooks vs. laptops vs. tablets debate. The real story might be whether Apple can take a much bigger slice of the business IT market. Its hardware certainly seems up to the job.