hiding data behind images.

The art and science of hiding information by embedding messages within other, seemingly harmless messages. Steganography works by replacing bits of useless or unused data in regular computer files (such as graphics, sound, text, HTML, or even floppy disk ) with bits of different, invisible information. This hidden information can be plain text cipher text or even images.
1. 
Create a folder in your D drive and name it as “pic”.
2.
Copy all the images you want to hide and also the image behind which you want hide into this directory.
3.
open the notepad and write any message you want to hide.and save with test.txt.
4.
open the command prompt and write the command
 d:/>copy pic.jpg+test.txt  pic.jpg
5
here d. is the current directory where you save the image and message.
6.
now when you open the pic with notepad you can see the message you have write. otherwise the image will open as it is.