Modern networks function reliably because both devices and software follow established rules. These rules are defined by standards and protocols. A protocol is a formal agreements that specify how particular aspects of a network should operate. Due to the vast number of such protocols and standards, understanding and managing networks can become complex. To bring structure to this complexity, the networking field relies on conceptual frameworks known as networking models.

Networking models, such as the OSI and TCP/IP, organize protocols and standards into logical layers, each with distinct roles and functions. These models not only guide the development of new technologies but also provide a reference for understanding how different network components interact. For example, when new protocols are introduced, network professionals interpret them within the framework of these models to maintain consistency and interoperability.

Today, the TCP/IP model is the dominant standard across the industry. It is supported by virtually all operating systems, from smartphones to enterprise servers, and forms the foundation of all networks built with Cisco equipment. Accordingly, TCP/IP is central to the CCNA certification, and this course leverages the model to explain core networking concepts in a structured manner.