In GWT we can use ClientBundle to load all the images and CSS files in one single file and use it anywhere in the application. It provides flexible way to get the resources.

1. It creates a single image from the collection of images at compile time to reduce the image size.

2. Enable more aggressive caching headers for program resources. It will go to server for every-time to get the images.

3.Eliminate mismatches between physical file names and constants in Java code by performing consistency checks during the compile.