Definition - What does Public Network mean?
A public network is a type of network wherein anyone, namely the general public, has access and through it can connect to other networks or the Internet. This is in contrast to a private network, where restrictions and access rules are established in order to relegate access to a select few. Since a public network has few or no restrictions, users need to be wary of possible security risks when accessing it.
Techopedia explains Public Network
A public network is a usage designation rather than a topology or other technically related principle. There is no technical difference between a private and public network in terms of hardware and infrastructure, except for the security, addressing and authentication systems in place.
Because any user can connect to a public network, its level of security needs to be heightened and various anti-threat and malicious act precautions must be put in place. Because anyone is able to access the network, malicious users may try to infiltrate the systems of unsuspecting users. Many company secrets have been stolen from executives using their laptops in coffee shops with public Wi-Fi.