How to modify the background image in iPhone?

I am using iPhone 4S now. But I don’t know how to change the background image of my iPhone. Please let me know how it can be done.

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Here is a systematic procedure that you can follow for changing the background image of your iPhone.

• First thing you have to do is to select the image
• Once the image is selected, you will have to set it as Wallpaper
• The default wallpapers can be enabled by tapping the ‘Set’ button
• For images in the camera roll, you will have to click on the image and then click on the icon being denoted towards the bottom left which looks like an arrow
• Select ‘Use as wallpaper’
• The tap ‘Move’
• Tap ‘Scale’
• Finally tap ‘Set Wallpaper’

You have the new background enabled in your iPhone.