Over the last few decades, PCs have had a considerable lead over Apple's Macs in terms of sales. When Microsoft introduced Windows 95, the discrepancy between the two platforms became even more apparent as the easy-to-use operating system made its way into millions of households, but during the early 2000s, the momentum had shifted in Apple's favor. According to analyst Horace Dediu, at its peak, PCs outsold Macs by 55 times in 2004, a number that dropped to about 20 times as many PCs in 2010.
Whether it be a result of the iPod's release in 2001, the company's new line of iMac computers, or the quickly increasing presence of the internet, something had made people start to care more about Apple's products — or, possibly, care less about Windows and PCs. What may be even more important is that, when taking into consideration the amount of iPhones and iPads sold in the recent years, Apple's products and PCs are almost neck and neck, which is particularly important as momentum shifts into the "post-PC era" (although with the release of Windows 8 and Surface this year, Microsoft hopes to get back into the game). What this means for the platforms in the long run remains to be seen, but Dediu has provided an in-depth comparison of the two that you can check out at Asymco's site.