Publisher Summary Connectivity and networks are an important area in embedded systems. This chapter deals with issues of connectivity and networking – the medium of connection used to create data links, and the means by which data is actually formatted, moved, and interpreted over those links. Providing a network is about much more than just providing connectivity. In a complex system it is also essential to deal in depth with how data is formatted and interpreted, how addressing is achieved, and how error correction can be implemented. All of this is pretty much independent of the physical interconnection itself. For different nodes to communicate on a network, there must therefore be very clear rules about how they create and interpret messages. The chapter explains some underlying concepts of setting up a network and alternatives for connectivity, including the wireless options of infrared and radio. It introduces the reader to a range of network protocols. It also informs that how peripheral interface controller (PIC) microcontrollers can be applied in these areas.