Embedded systems are computer hardware and software systems that have a specific function within a larger system. This can include everything from home appliances like a microwave to large industrial machinery. Embedded systems are used in SCADA and other ICSs. The hardware in an embedded system is typically more consolidated and less complex than a traditional computer.

In order to best support this lack of hardware complexity, embedded operating systems focus on maximizing resource efficiency. They tend to be heavily stripped down versions of standard OSs with fewer features. As a result, embedded OSs rarely incorporate robust security practices. Embedded Linux distributions and Windows Embedded Compact are popular examples of embedded OSs.

For the purposes of exploitation, many of the reconnaissance tools you've used to discover information on traditional computers will be useful for targeting embedded OSs. For example, you can discover open ports and running services by performing a scan of the system. Embedded OSs often come with a web-based interface for configuration, and as such may be susceptible to various web-based exploits.