It is the programming of an embedded system in some device using the permitted programming interfaces provided by that system. EmbeddedJava is an example of a development environment for programming embedded systems that will execute Java programs.
Embedded system is a widely used term in the modern Information Technology. How is an embedded system defined? According to SearchEnterpriseLinux.com "An embedded system is some combination of computer hardware and software, either fixed in capability or programmable that is specifically designed for a particular kind of application device. Industrial machines, automobiles, medical equipment, cameras, household appliances, airplanes, vending machines, and toys (as well as the more obvious cellular phone and PDA) are among the myriad possible hosts of an embedded system. Embedded systems that are programmable are provided with a programming interface, and embedded systems programming is a specialized occupation"