The internet has become one of the most important components of our life. We browse the web, check e-mails, make VoIP phone calls, and have video conferences via computers. All of these applications are made possible by networking computers together, and this complex network of computers is usually referred to as the Internet. This course is designed to give you a clear understanding of how networks, from in-home local area networks, or LANs, to the massive and global Internet, are built and how they allow us to use computers to share information and communicate with one another.

Unit 1 introduces you to an explanation of what computer networks are as well as to some basic terminology fundamental to understanding computer networks. You will also familiarize yourself with the concept of layers, which compose the framework around which networks are built. Next, Unit 2 explains the concept of protocols. A computer communication (or network) protocol defines rules and conventions for communication between network devices.

The rest of the course implements a top-down approach to teach you the details about each layer and the relevant protocols used in computer networks. Beginning in Unit 3, you will explore the concept of application layer protocols, which include the Domain Name System, e-mail protocols, and the Hypertext Transfer Protocol. Unit 3 ends with an overview of how to use socket programming to develop network applications. In Unit 4, you will learn transport layer protocols, including the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). You will go on to study the network layer Internet Protocol (IP) and packet routing protocols in Unit 5. Next is Unit 6, which is devoted to a discussion on link layer protocols, and the course concludes with an overview of voice and video protocols, network security, and cloud computing in Unit 7.

As you move through the course, take time to notice how the layers build on top of one another and work together to create the amazing tool of computer networks, which many of us depend upon daily.