Internet Printing Protocol
The Internet Printing Protocol or IPP, defines a standard protocol for printing as well as managing print jobs, media size, resolution, and so forth.
Like all IP-based protocols, IPP can be used locally or over the Internet to printers hundreds or thousands of miles away. Unlike other protocols, however, IPP also support access control, authentication, and encryption, making it a much more capable and secure printing solution than older ones.
It faces criticism for its protocol overloading, because it is build on HTTP. This makes for a more complex and bloated protocol and implementation than necessary — if for example the venerable lp protocol was extended to cover the same functionality —, even if it is convenient to reuse implementation components such as HTTP servers.