If i am not mentioning the images at network section in manifest file then my images are not getting loaded

If i didnt mention the image URL under the network section, then my images are not getting loaded during online also. I don't know why.

This is my manifest file: offline.appcache

"CACHE MANIFEST

cache:

login.jsp

SignUp.jsp

FALLBACK:

LoginSuccess.jsp offline.jsp"

At-least I should mention below code to make my images load.

NETWORK: *

As I studied, NETWORK section is for "The list of files which you don't want to cache". * means other than the files listed under CACHE section, don't cache any other files.

Why I should mention Images under the NETWORK section? can anyone please explain.