An embedded system is a combination of hardware and software designed for a specific task. It is made up of a processor, memory, input/output devices, and application software. Embedded systems are used in devices like household appliances, medical equipment, vehicles, and more. They are designed to perform dedicated functions in real-time, making them more reliable, efficient, and cost-effective than general purpose computers. Common processors used in embedded systems include Intel 8051 and ARM. Development tools include assemblers, compilers, debuggers, and simulators.