iPhone User Guide : Rearranging Icons (move, delete, group)
You can arrange the icons on your Home screen in any order you want.
1.Touch and hold any icon on the Home screen until it begins to jiggle.
2.Arrange the icons by dragging them.
3.Press the Home button to save your arrangement.
You can also add links to your favorite webpages on the Home screen.
Move an icon to another screen: While arranging icons, drag an icon to the side of the screen.
Create additional Home screens: While arranging icons, flick to the rightmost Home screen, then drag an icon to the right edge of the screen until a new screen appears.
You can create up to 11 screens. The number of dots above the Dock shows the number of screens you have, and which screen you're viewing.
Reset your Home screen to the default layout: Choose Settings▷General▷Reset and tap Reset Home Screen Layout.
Resetting the Home screen removes any folders you've created and applies the default wallpaper to your Home screen.
Organizing with Folders
Folders let you organize icons on the Home screen. You can put up to 12 icons in a folder. iPhone automatically names a folder when you create it, based on the icons you use to create the folder, but you can change the name anytime you want. Like icons, folders can be rearranged by dragging them around the Home screen. You can move folders to a new Home screen or to the Dock.
Create a folder: Touch and hold an icon until the Home screen icons begin to jiggle, then drag the icon onto another icon.
iPhone creates a new folder that includes the two icons, and shows the folder's name. You can tap the name field and enter a different name.
Quotation: iPhone User Guide