By comparison, a signature is a stylized script associated with a person. In commerce and the law, a signature on a document is an indication that the person adopts the intentions recorded in the document. Both are comparable to a seal. In many instances, common with engineering companies for example, digital seals are also required for another layer of validation and security.
Network Address Translation (NAT) is a way to map an entire network (or networks) to a single IP address. NAT is necessary when the number of IP addresses assigned to you by your Internet Service Provider is less than the total number of computers that you wish to provide internet access for. NAT is described in RFC 1631. NAT allows you to take advantage of the reserved address blocks described in RFC 1918.
The outside refers to the external-facing network interface, the one that receives ingress traffic. In the real world, it is not the case that NAT is simply using a single outside IP; translating traffic into internal IPs and ports. That's what your Linksys router does. Key Terms To Understanding NAT and PAT: NAT Short for Network Address Translation, an Internet standard that enables a local-area network (LAN) to use one set of IP addresses for internal traffic and a second set of addresses for external traffic. PAT Short for port address translation, a type of network address translation.