Explain the concept of Masquerading and in what cases it is used in security systems?

Masquerading is a technique in security systems and network administration where one computer or device masks (substitutes) its IP address with another, usually to hide the real address or to provide access to resources through a shared external address.

Most often, masquerading is used in networks with NAT (Network Address Translation), where several devices inside a local network access the internet through a single external IP address. In this case, the router replaces the source IP address of packets with its external address and maintains a translation table to correctly redirect responses back.

Applications of masquerading:

• Security assurance — hiding the real IP addresses of internal devices.
• Saving public IP addresses.
• Organizing internet access for multiple devices through a single external address.

Example: a home router with masquerading allows all devices in the local network to use one external IP to access the internet.