Hi anees kader,
The article below should answer your question.
You can click on the link to see more details and screen shots.
I've highlighted the pertinent information for you below.
iOS: About the Cellular Data setting
http://support.apple.com/kb/HT4203
From the Home screen:
- iPhone: Choose Settings > Cellular
Understanding and adjusting data usage
You can also enable or disable cellular data for certain iOS apps and features from this setting.
Contact your carrier if you have questions about your cellular data usage.
I hope this information helps ....
Have a great day!
- Judy