The Start screen apps are initially displayed in a fairly random order, but if you’d prefer a more organised life then it’s easy to sort them into custom groups.
You might drag People, Mail, Messaging and Calendar over to the left-hand side, for instance, to form a separate ‘People’ group. Click the ‘minus’ icon in the bottom right corner of the screen to zoom out and you’ll now find you can drag and drop the new group (or any of the others) around as a block. Right-click within the block (while still zoomed out) and you’ll also be able to give the group a name, which – if you go on to add another 20 or 30 apps to your Start screen – will make it much easier to find the tools you need.
Windows 8.1 now provides a special Customise mode with much the same functionality. Right-click an empty part of the Start screen, or swipe up, tap Customise, then drag and drop tiles or rename app groups to whatever you need.