The embedded systems are widely used nowadays. Like other mechanical systems, automotive systems have been developed to include a considerable amount of embedded systems. The present article provides an overview of the embedded systems and their role in industry. Starting from definition, usage, requirements, types and components, the embedded systems are explained in a nutshell. Also, in this paper, some tools that are used in embedded systems testing and evaluation are explored, like Arduino and Raspberry Pi, while stating the differences between microcontrollers and microprocessors. In addition, suitable methods for using the embedded systems along with the required procedures to develop an embedded system are discussed. The embedded systems in automotive applications are highlighted referring to the currently used protocols and networks. Classification of communication protocols used in automotive systems is discussed. As a case study, a suitable network/protocol is illustrated explaining its capabilities and usage. The present article is a simplified guide for mechanical engineers interested in automotive research.