Yes, I know you have seen this in other blogs too, so what is new here. Let me tell you, all other blog writers intend to give you simply a trick that they knew but here I intend to give the reason behind these tricks. I will tell you the reason that why this command resulted in this way. So, Are you ready to know how you can hide your files in a photo.
For this trick, U require Winrar. U can get it from internet.
Firstly, copy all the files that U want to hide to a new folder. Now compress it through the Winrar.
Put this compressed folder to the location where the jpg file is situated in which you want to hide the file.
I assume that you know little bit about Command Prompt. You only need to reach the location of the folder where you have kept both the files. If  you do not know how to use the Command Prompt, in this case U need to use only one command “cd”. Through Cd U you can reach the destination. cd takes you a step further in the current directory list and cd.. takes you down.
When you are there type the fallowing command in the command prompt.
copy /b  source.jpg  tohide.rar  destination.jpg
here source.jpg is the file where you want to hide the files.
tohide.rar is the file that you want to hide.
and destination.jpg is the result file having your hidden files.
When you will open the destination file through the any image viewer software, you will see the original picture that was in the source.jpg
And when you will open this file with WinRar, you will see the hidden files.
Now, time is for some explanations……………………….
The command copy is the command used in Command Prompt to copy two files. Its parameter /b here tells the computer to merge all the binary information into a single file. So, it is the reason that the destination.jpg has the information of both the file.There is a proof also that the destination file has the binary information of both the source files.
Note down the exact size of the source.jpg and tohide.rar, you will see that the size of the destination.jpg is exact sum of the other two.
The image viewer software reads the destination.jpg to the point to which the binary information of a photo is there and WinRar reads for here to the point where Rar concerned file is writtem.
So, I guess that I made you understand the logic behind this trick.