An embedded device is an object that contains a special-purpose computing system. The system, which is completely enclosed by the object, may or may not be able to connect to the Internet.
Embedded systems have extensive applications in consumer, commercial, automotive, industrial and healthcare markets. It's estimated that by 2015, over 15 billion embedded devices will be connected to the Internet, a phenomenon commonly referred to as the Internet of Things.
Generally, an embedded device's operating system will only run a single application which helps the device to do its job. Examples of embedded devices include dishwashers, banking ATM machines, routers, point of sale terminals (POS terminals) and cell phones. Devices that can connect to the Internet are called smart or intelligent. If an embedded device can not connect to the Internet, it is called dumb.
Embedded devices in complex manufactured products, such as automobiles, are often headless. This simply means that the device's software does not have a user interface (UI). In such cases, an in-circuit emulator (ICE) is temporarily installed between the embedded device and an external computer to debug or update the software.
Because embedded systems have limited computing resources and strict power requirements, writing software for embedded devices is a very specialized field that requires knowledge of both hardware components and programming.