Defining what a computer network is and its primary objectives.
A computer network is a collection of two or more interconnected computing devices that can exchange data and share resources. These 'computing devices' can be anything from servers, desktops, laptops, and smartphones to more specialized hardware like routers, switches, and IoT devices. The 'interconnection' is achieved through a physical medium, which can be wired (like Ethernet cables or fiber optics) or wireless (like Wi-Fi or cellular signals). The fundamental goal of networking is to enable seamless communication and resource sharing. Resource sharing is a broad term that includes sharing hardware (e.g., a single printer shared among all employees in an office), software (e.g., accessing a centralized database or application server), and data (e.g., sharing files on a server or collaborating on a document in the cloud). Beyond resource sharing, networks provide high reliability by having alternative sources of supply (e.g., replicated files on multiple machines). They also offer scalability, allowing performance to be enhanced by adding more processors or devices. Another key goal is to provide a powerful communication medium for people, as seen with email, instant messaging, social media, and video calls. Essentially, networks overcome the barrier of geographical distance, making information and services accessible regardless of the user's physical location.