Most new technologies foster improved product performance. I call these sustaining technologies. Some sustaining technologies can be discontinuous or radical in character, while others are of an incremental nature. What all sustaining technologies have in common is that they improve the performance of established products, along the dimensions of performance that mainstream customers in major markets have historically valued. Most technological advances in a given industry are sustaining in character…

Disruptive technologies bring to a market a very different value proposition than had been available previously. Generally, disruptive technologies underperform established products in mainstream markets. But they have other features that a few fringe (and generally new) customers value. Products based on disruptive technologies are typically cheaper, simpler, smaller, and, frequently, more convenient to use.

• The PC was disruptive to nearly all of the existing incumbents; these relatively inexpensive and low-powered devices didn’t have nearly the capability or the profit margin of mini-computers, much less mainframes. That’s why IBM was happy to outsource both the original PC’s chip and OS to Intel and Microsoft, respectively, so that they could get a product out the door and satisfy their corporate customers; PCs got faster, though, and it was Intel and Microsoft that dominated as the market dwarfed everything that came before.
• The Internet was almost entirely new market innovation, and thus defined by completely new companies that, to the extent they disrupted incumbents, did so in industries far removed from technology, particularly those involving information (i.e. the media). This was the era of Google, Facebook, online marketplaces and e-commerce, etc. All of these applications ran on PCs powered by Windows and Intel.
• Cloud computing is arguably part of the Internet, but I think it deserves its own category. It was also extremely disruptive: commodity x86 architecture swept out dedicated server hardware, and an entire host of SaaS startups peeled off features from incumbents to build companies. What is notable is that the core infrastructure for cloud computing was primarily built by the winners of previous epochs: Amazon, Microsoft, and Google. Microsoft is particularly notable because the company also transitioned its traditional software business to a SaaS service, in part because the company had already transitioned said software business to a subscription model.
• Mobile ended up being dominated by two incumbents: Apple and Google. That doesn’t mean it wasn’t disruptive, though: Apple’s new UI paradigm entailed not viewing the phone as a small PC, a la Microsoft; Google’s new business model paradigm entailed not viewing phones as a direct profit center for operating system sales, but rather as a moat for their advertising business.