This page will contain highlights of info, with references to more descriptive information if you so desire. Just keep in mind, your eye can only see so much. On top of that, the hardware that you have, with which you view images on the Net may be limited. To get the best view you need excellent eyesight, lots of memory in your PC and a top of the line graphics card. The first item you have no contol over and the last two cost a lot of money.

RGB

Red, Green, Blue. The three basic colors that combine to make up all the others.

PNG

PNG, Portable Network Graphics, was developed in response to Unisys wanting a license for use of GIF. Like happens so many times, wizards got together and developed a patent free, open software version. At this time it doesn't handle animations but I'm sure that is not far off. But, on the other hand, it may never get developed. Flash, which got less expensive through KoolMoves, may be heavily used instead.

GIF

GIF, which stands for Graphic Interchange Format, was one of the first graphic formats for the Web. It is a 256 color, bit-mapped format, that uses LZW compression to keep the images small. It also supports transparancy. This allows you to make the background of an image invisible so that you may place it on top of another. And along with this we have the support for interlacing. This will display your image in layers as the WebPage is loading. Your visitor won't have to wait for the whole image to load in order to see what is happening. The graphic doesn't load any faster but, it appears to. Its compression method is lossless. Lossless compression retains all of the original image data and reduces the file size by storing patterns of pixels in the image.
Also See: lossless compression
Animation
Gif animation is really nothing more than a series of pictures that are displayed one after the other. You, the artist, must make the changes. Like if you wanted to have a spinning propeler on your WebPage. The first image would be the prop straight up and down, the second with it at 45 degress, the third with it at 90 degrees, the fourth at 135 degrees and so on until you have made a complete revolution. This simple item would take 8 pictures. The speed at which the prop spins would be dependent on the length of time each pic was displayed. Of course this is just a ruff one. To make a cleaner showing would require more pics, at closer angles, which would require more memory. Each picture occupies space. If you don't have a lot of RAM the animation can get quite jerky and your hard disk will do a lot of thrashing.

JPEG or JPG

JPEG, Joint Photographics Experts Group. This format supports 16 million colors, most of which you can't see or they are not displayed by your graphics card or monitor. However, the smooth transition from one color or shade to another is quite impressive. Because of the way it handles compression, (Lossy compression: a compression method that eliminates data to reduce the file size) it is very good for photos but not good for text. It also has a progressive form that will allow it to load in layers instead of having to wait for the whole thing at once.
Also See: lossy compression

Flash

Vector-graphic animation from Macromedia. (Also KoolMoves) As long as different browsers are equipped with the necessary plug-ins, Flash animations will look the same. With Flash, users can draw their own animations or import other vector-based images.
Also See: FLASH... or Not