Everyone has his or her own impression of what multimedia is. Some think of it as a slide show set to music, others see it as an interactive retail kiosk, and still others believe it is a video game at home on a TV screen. There is no right or wrong definition, it is a continuum of applications and technologies that allow for a wide range of experiences.

In its most basic definition, multimedia can be thought of applications that bring together multiple types of media: text, illustrations, photos, sounds, voice, animations, and video. A combination of three or more of these with some measure of user interactivity is usually thought of as multimedia computing.

A medium is a way of communicating. We call TV multimedia, because it includes both audio information and video information.

In computer circles multimedia has come to mean the simultaneous delivery of audio and video information: a movie (or video) that shows on your computer.

The power and promise of multimedia is that it gives control to the end user. Once content in various media forms is combined, it can be made interactive. Users can begin to navigate and choose relevant information for themselves.

Multimedia is really not such a new medium, but rather old individual media that have come to life together in new formats on new devices and for new personal uses.

The whole focus of the industry in the late 1970s was the business of making computers do things. It was all technology and programming. Then the Macintosh computer came along and popularized the graphical user interface. All of a sudden, the computer changed from being 100% code and all technology to 80% code and 20% graphics. Graphic design and user interface metaphors were part of the mix. It wasn't just a matter of writing code, you had to have artists to make drawings. This spawned a number of applications that took advantage of the incorporation of graphics in programming, desktop publishing and presentations, for example. Now we are at a point where we are incorporating all of these dynamic media and developing content. The whole ratio flops around. The graphics and dynamic media become 80% and the programming is 20%.

The multimedia industry today is comprised of numerous applications of multimedia across many different markets. Multimedia applications are now categorized into seven major application solutions.

These seven general market solutions allow us to view the full spectrum of multimedia projects or products for multimedia developers. These classifications cut across market boundaries, such as home, business, education, and government.

The classifications can never be exact, since there are many areas of overlap between these segments.

For example, an interactive brochure for a travel agency might be viewed both as an information management tool, like a kiosk, and as a communications and sales presentation tool for the travel agent.

The seven application solutions are:

• Electronic Publishing; Electronic Books, Electronic Magazines.
• Communications; Presentations, Interactive Sales & Marketing, Enhanced Productivity tools, Desktop Videoconferencing.
• Interactive Learning; Higher Education, Corporate Training
• Authoring & Creating; Authoring Tools, In-House Corporate Applications, Home Video Authoring
• Interactive Entertainment; Interactive Games, Interactive Art, Interactive Film, Interactive Music
• Visualization; Scientific Visulisation, Engineering/Manufacturing Architectural Rendering & Walkthrough
• Information Management; Interactive Kiosks, Multimedia Databases

Multimedia is turning out to be one of the most appealing things that computers do. Since the beginning of the 90s, the home computer market has been growing much faster than the business market, and multimedia titles have become the hottest segment of the software industry. Moreover, most computers that are being sold today come out of the box already equipped with the add-on peripherals (hardware) that make multimedia applications possible, or more fun: sound boards, speakers, CD-ROM drives, big-screen color monitors, plenty of memory, and a fast processor (CPU). And almost all of these computers have Windows, the most popular multimedia platform in the world - preinstalled on their hard disks.

Most of the time, the audio component of a multimedia application is played through a sound board, a specialized piece of hardware that's designed to convert digital stereo audio information into high-quality analog sound that can be played through a pair of good sounding speakers.

Ideally, you view the video portion of a multimedia application on a big screen color monitor that's driven by a fast video board.

Most of the time, multimedia applications come on CD-ROMs because the files that hold audio and video information are so big that they don't fit easily on floppy disks.

Frequently, the visual part of a multimedia application is taken from an actual film or video that's digitized to show on your computer, but not always. And although a lot of PC multimedia is interactive (which means that by clicking your mouse or pressing a key you can change the way the show is performed), it doesn't have to be.

Why is multimedia suddenly such a big deal? Partly because multimedia is fun - and here at the century's end, people seem to be spending a lot of money and time entertaining themselves. But it's also true that as information (and the time needed to access it) grows more precious, multimedia is becoming one of the most effective ways of getting that information. After all, if a picture is worth a thousand words, a full-motion animation with voice-over narration and background music must speak volumes.

As everyone knows, movies don't really move; they flash a series of still frames in front of your eyes quickly enough to create the illusion of motion. In most countries, TV puts 30 frames on the screen every second; movies use 24 fps. In the early days of the century, silent films were projected at 16 fps (frames per second) which still produces a perfectly acceptable illusion of motion.

In the world of multimedia, full-motion video is supposed to mean 30 fps - the same frame rate as TV. But it hardly ever does. In most cases, "full-motion video" on the box merely means that some kind of video is included, and often it's video that is shown at a choppy 6 or 8 fps in a video window that's half the size of a credit card.

The reason most multimedia video isn't better is that getting video frames off a CD and onto your computer screen is difficult and time consuming. Majorities of the personal computers are not capable of showing 30 fps, so it's not worth the time and trouble for software vendors to build a full-motion frame rate into their applications. Having said that there are some video card manufacturers who are trying to get the smooth motion picture effect, but at the time of writing, they are still a bit on the expensive side. This is why codec is used. Compression and decompression (codec) are inescapable facts of multimedia life, and both of them can be major issues when you're trying to optimize performance or troubleshoot problems.

I wouldn't want to bog you down with the math details, so trust me on this: It takes a lot of data to fully describe the colors, brightness, tones, and shapes in a single frame of a video image. Putting even a quarter-screen of uncompressed video onto your monitor at 15 fps requires about 3.4MB of data per second, or 230K per frame. That’s mainly the reason why the data off the CD-ROM does not get off fast enough. Of course the newer CD-ROMs with faster speeds are close enough to give you the feeling of smooth video transfer.

Putting multimedia on your computer screen demands that a number of complicated technical events occur flawlessly and in perfect coordination. And none of them is easy to bring about.

As explained above, you have to get a lot of sound and video information of the CD-ROM and into the PC. Then you need to decompress that information, which takes high-speed number crunching at a time when the PC's primary number cruncher, the CPU, already has its hands full getting the data off the CD-ROM in the first place.

After the data is decompressed, audio needs to be split off and sent to the sound system, video needs to go to the display, both audio and video data may need to swap into and out of main memory during this process, and the overburdened CPU needs to oversee a lot of what is going on.

Finally, audio and video need to be coordinated with each other, and with your mouse and keyboard input.

So although advanced multimedia applications have been on the market for several years, computer hardware is just now becoming capable of delivering the horsepower necessary to run them well. It's only been a few years since sound boards, video systems, and fast CD-ROM drives have become common, along with systems that have enough memory and computing power to run compression and decompression software.