Progressive display: When a web page loads an image it takes some time. Usually it is displayed when it is fully downloaded or it is displayed downloading from top to bottom. There’s another technique to handle the downloading of the image in the web. It is known as Progressive display. In this process the initial image is downloaded as a blur image and after a few seconds the image fully downloads in the page. A user views it as an improvement of the image quality.
Interlaced GIF image: It is a GIF image which supports progressive display. Interlacing is done in GIF images to provide a sort of a blur preview of the image in the web. A user can check the blur image, if he chooses to move ahead he could do that and also if he likes the image he can hold on until it is fully downloaded in the page.
Progressive JPEG: It is a JPEG image which supports progressive display. Interlacing is done in JPEG images to provide a sort of a blur preview of the image in the web just like Interlaced GIF image.
Transparency: Transparency is an image effect in which the background of a particular image is made transparent. So when the image is loaded in a page it takes the background color of the particular web page. Transparency is supported by GIF and PNG formats. However it is not supported by JPEG format.