In graphics and image-editing programs, image effects are predefined algorithms that enable you to add special effects to your images. The actual effects will depend on the software you use. You can usually choose different effects that will change the edges of your image, noise level, gradient and other aspects of your image.
With most programs you can simply select the name of the image effect and the program will produce the image with the effect, then you can save the changed image. You can also choose undo if you don't like it and select another one to try. Also, you may find your program offers an effects browser, which will open your image as a thumbnail in a browser window that allows you to quickly preview how each effect will look before performing the action. Image effects are used as a way to change your image to add an artistic look, make textured patterns, or produce an enhanced real-world view. Some graphics programs will offer a few predefined effects, others designed with effects in mind may offer hundreds of image effects to choose from.