i want to know what are the different between jpg and gif formate. also about new trend of web2.

Jai,

The most significant difference between .gif and .jpg is the number of colors supported by the two formats. For the .gif format you are limited to 256 colors while the .jpg format supports up to 24-bit (16.7 million) colors. As you can imagine, a photograph will look better saved as a .jpg than it would saved as a .gif.

Some other differences are:
1) .gif supports transparency, .jpg does not.
2) .jpg can be compressed significantly but does lose resolution, .gif doesn't compress as much.

I have intentionally left out a "new" format as I will introduce it now in talking about "Web 2.0".

Web 2.0 has been used to describe many things about web development, including layout style and active content. Any site that uses AJAX (Google Maps, Kayak, etc.) has been calling itself a Web 2.0 site. There also seems to be a design style associated with Web 2.0 which includes the glassy buttons, rounded corners, etc. Apple.com is a good example of this.

The design style of Web 2.0 has been made possible by the wide-spread acceptance of a graphics format called Portable Network Graphics or .png for the extension. Like .jpg, it supports a 24-bit color range and adds "alpha-transparency", a feature that is supported in most browsers with the notable and frustrating exception of IE6.0.

If you look at my site - www.castagna.net - you will see my company logo laid on top of a background photo that spans the top of the site. These are actually two graphic images - the photo being either a .png or .jpg and the logo being a .png. Because of the transparency capabilities of .png you can see that the logo does not have any hard edges and blends very pleasantly with the image behind it. On some of the lighter photos, you can even see the drop-shadow of the logo on the image behind it.

There are new and cool things happening every day in web development. I encourage you to monitor Quomon and other sites and just learn as much as you possibly can in a day. Feel free to call on others for assistance as you've done here.

If you need any direct help, please feel free to contact me. I spend quite a bit of time mentoring other developers and can be engaged for short-term consulting assistance on projects as well.

Take care,
Ric