Erik's point two "you do not know that a computer is involved" says it all. Put in another way, embedded system is more device-oriented, and can be programmed to perform specified logic operations. Even a PC itself has many embedded systems within, for example, keyboard, monitor, and CDROM. Some embedded system simply uses a PC box (running with DOS or other OS) for complex programming and integration.

Many of the embedded systems are designed for real-time processing. Real-time means that the system must respond to the event within a defined period of time. For example, your digital alarm clock is real-time, and your web-browsing is not real-time.

Happy Holiday,
Oliver