What flavor of network address translation can be used to have one ip address allow many users to connect to the global internet?

The simplest type of NAT providing a one-to-one translation of IP addresses refers to basic NAT type, which is often also called a one-to-one NAT.

In this type of NAT only the IP addresses, IP header checksum and any higher level checksums that include the IP address are changed.

The rest of the packet is left untouched (at least for basic TCP/UDP functionality; some higher level protocols may need further translation).

Basic NATs can be used to interconnect two IP networks that have incompatible addressing.