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.
What Is Network Address Translation? NAT was originally developed as an interim solution to combat IPv4 address depletion by allowing globally registered IP addresses to be re-used or shared by several hosts. The classic NAT defined by RFC 1631 [3] maps IP addresses from one realm to another. Although it can be used to translate between any two address realms, NAT is most often used to map IPs from the nonroutable private address spaces defined by RFC 1918 [4] , shown below.