There are many formates available on the internet of different images. Every formate has its own benefits. There are two types of graphics which are used. One is Bitamp. Bitamp images are pixel based. It is resolution dependent. When we zoom any Bitamp image then we can loose the quality and details of the data. JPEG formate is mostly used when we need small size image. Most photographers uses this formate to store his data. This formate should not be used in logos, line art and wide areas of flat color. GIF is another one. This formate is used when we use animated effects. When we need transparency then GIF is the best choice. In clip art, flat graphics and images that use minimal colors and precise lines, GIF, is the best choice. PNG is another one. In this formate there is no chance of losing data. When we need logos for our company then this formate is the best choice for us. One drawback of this is that this is not supported everywhere.Vector based images are not resolution dependent. After zooming we will not loose the quality of the image. On the web we can find this in the form of SVG. This is also used when we need small file in compressed formate. We can scale the image into any size without losing clarity of the image. When logos are built in this mode they seem perfect.
http://download.cnet.com/Free-JPG-to-PDF-Converter/3000-2010_4-75732662.html