Meaning – The term line printer daemon, refers to a printer protocol that is used to connect workstations and printers over a TCP/IP network. While LPD was primarily created for Linux and Unix systems, it is now the De Facto Standard for printer communications across platforms.
An LPD printer is identified by the IP address of the server machine and the queue name on that machine. Many different queue names may exist in one LPD server, with each queue possessing unique settings. It must be noted that the LPD queue name is case-sensitive. Some modern implementations of LPD on network printers might ignore the case or queue name altogether and send all jobs to the same printer. Others have the option to automatically create a new queue when a print job with a new queue name is received.
Example of usage – “A server for the Line Printer Daemon protocol listens for requests on TCP port 515. A request begins with a byte containing the request code, followed by the arguments to the request, and is terminated by an ASCII LF character.”