An embedded system is a computer built for one specific purpose, as
opposed to a PC which is built for general purposes and can be used for
many things (like watching movies, reading email, surfing the net, etc.)
One device can have one or several embedded systems. A great example is
a car. A car can have one embedded system to control the anti-locking
brakes, another to control the automatic four-wheel drive, one to
control the heater and air conditioner, and a multitude of other
devices. Embedded systems are great for things that just have one
purpose, and it is especially great for tasks which are repetitive and
have to be precise (such as the anti-lock braking systems.) Equally,
embedded systems are applied to transportation, medical applications and
fire safety equipment because they can perform their tasks accurately
in real-time without any delay and almost without any need for outside
input.