NAT - Network Address Translation
Network address translation enables computer systems in the internal network use unregistered IP addresses. This public unregistered IP address can be used for internal communication i.e within the internal network only. To enable these devices use the Internet, a router needs to map these unregistered IP addresses to registered public IP addresses. This process of IP address mapping is known as Network Address Translation (NAT).
NAT helps in reducing the IP address requirement for an organization and improves the security by hiding the entire internal network behind a single IP. In the best case, only one IP address is required for hundreds or thousands of computers for Internet connectivity. It also reduces the cost of the overall system.
How does NAT works
Network address translation makes use of the router through which packets are forwarded to the internal as well as external network. If the destined machine lies in the internal network, the router needs not to change the IP address of the packet and forwards it to the destination.
In the other case, if the destination network lies outside the internal network, the router makes a request using another IP address which is common for all the systems in the internal network. The process of NAT looks quite complex, but happens rapidly.
NAT - National Aptitude Test
National Aptitude Test is India's national level, common entrance test, conducted by the aegis SRDE Association of Higher Education Institutions (SAHEI) Delhi. The 'National entrance test' is conducted in 2 forms: NAT-UG and NAT-PG, for admission to various graduate and post graduate courses respectively. These courses include: BBA, MBA, B.com, M.com, BCA, MCA, PGDBM and many more.