One is a functional definition and the other is a technical definition.
The former defines a LAN as a group of desktop computers and other devices that are not physically separated from one another to allow users to interconnect systems that allow users to communicate with each other and share computing resources such as printers and storage devices. This definition applies to LANs used in office environments, factories, and research institutes. (emphasis on outside behavior and services)
For the technical definition of a LAN, it is defined as a computer that is interconnected by specific types of transmission media (such as cables, optical cables, and wireless media) and network adapters (also known as network cards) and is monitored by the network operating system. system. (emphasis is on the material basis and composition required to make up the LAN)