Image File Types.

GIF & Animated GIF files;
- One of the biggest creations in the history of the Internet was the ability to integrate photographs and other illustrations with text on a web page.
- The pictures come in the form of bitmap files. A bitmap file simply describes the colour of each pixel in the image. To decrease the file size of these bitmap images, several different techniques are used to compress the image data. Web sites post these sorts of images as either JPEG files or GIF files.
- Animation is just a series of still images shown in sequence, so the most obvious way to add animation to a Web site is to post a series of bitmap images that the user's browser displays in sequence. This sort of animation, called GIF animation, or GIF89, was the first Web animation to catch on, and it is still very popular today.
- The main advantages of GIF animation are that it is incredibly simple to work with and it is automatically recognizable to most Web browsers.
- With a program, such as GIF construction set for Windows or GifBuilder for Macintosh, all you have to do is provide the individual bitmap images that make up the frames of your animation. You then post the file and code the tag for the image, just as you would with an ordinary static GIF.
- The disadvantage is that you have to keep the animation pretty simple to keep the file size down. After all, each frame is a full bitmap image. Four simple frames transmit very easily to most users, but when you get up to something like 20 frames, your file size could be too big. And you can't even accomplish very much with 20 frames -- the fluid animation we see in movies includes at least 24 still images every second so animated GIFs are fairly limited. To create a movie of any substantial length, you have to make pretty big jumps between each frame, which means the animation is not very fluid.

JPEG files;
- JPEG is a commonly used method of lossy compression for digital photography.
- The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality.
- JPEG compression is used in a number of image file formats.
- JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG/JFIF, it is the most common format for storing and transmitting photographic images on the web.
- The term "JPEG" is an acronym for the Joint Photographic Experts Group which created the standard.

MPEG files;
- (Moving Picture Experts Group)
- In order to fit a movie on a DVD, you need video compression. A gorup called the Moving Picture Experts Group establishes the standards for compressing moving pictures.
- When movies are put onto DVDs, they are encoded in MPEG-2 format and then stored on the disc. This compression format is a widely accepted international standard. Your DVD player contains an MPEG-2 decoder, which can uncompress this data as quickly as you can watch it.

Shockwave files;
- Used on the web to present more complex animated content.

Difference between vector & bitmap;
- The most elementary kind of image in any discussion of vector and bitmap is the bitmap image, which sounds like something from the early days of computing, a map of bits. A bitmap image is quite literally a collection of squares that, taken together, make up the image. The squares might be of different colors, but they are all the same size. Reduce any bitmap image to its parts and you'll see this in detail.
- The other half of the vector and bitmap equation is the vector image. This kind of image is much more sophisticated because it has more moving parts. Each vector image is made up of a handful of smaller images, just like the bitmap, except that the vector image's parts are scalable. This means that designers can change the resolution of a vector image in both directions, making a high-res image lower or making a low-res image higher. If designers are looking for an image that can be easily scaled in both directions, then their choice between vector and bitmap should be an easy one.