Answer:
What seperates a LAN, MAN, WAN etc is actually the geographical area they cover. For example, a single computer with a mouse and a keyboard is a network, specifically a Personal Area Network or PAN. Now, technically speaking, the WAN is usually owned by an ISP which is responsible for providing high speeds and a stable connection. A "wider" network sometimes connect two smaller networks, for example a WAN can virtually connect two LANs (virtually means they are not directly connected with a single cable but they use the WAN to accomplish that).