Stateless
In computers, there are several topics that refer to stateless. One is a stateless protocol, which is a communications protocol that receives requests as individual, unrelated requests. The server receiving the communications does not retain session information or any status information for the communications. One example of a stateless protocol is HTTP.
There is also a stateless firewall, which is a firewall that does not retain any information about previous packets. The firewall doesn't know if any given packet was part of an existing connection, is attempting to make a new connection, or is a rogue packet. Due to this, stateless firewalls are vulnerable to spoofing attacks. An example of a stateless firewall is File Transfer Protocol (FTP).
Also see: Firewall, HTTP, FTP, Stateful firewall