Filler of stockings, saviour of publishing, compulsory accessory for the self-respecting executive: tablets are hard to ignore, as is the company that in 2010 finally made them a success: Apple.

Between unveiling the iPad in April and New Year’s eve next week, the company will have sold about 14m of its new toy, the most successful product launch in Apple’s history (it took more than three years for iPods to sell at the same rate). But beyond the immediate impact to Apple’s share price, the arrival of tablets marks the culmination of a long anticipated trend: convergence.

Assuming that the next version of the iPad contains a camera, there are now marked technological similarities among many types of devices: music players, phones, tablets and laptops. Indeed, this commonality has helped Apple expand its product lines with comparatively little research and development spending.