PCL levels 1 through 5e/5c are command-based languages using control sequences that are processed and interpreted in the order they are received.
[3] It consists of: PCL 6 "Enhanced" architecture was altered to be more modular and to be more easily modified for future HP printers, that it prints complex graphics faster, that it reduces network traffic, and has higher quality.
In early implementations, HP did not market PCL 6 well[citation needed], thus causing some confusion in terminology.
The plain-text commands and code examples shown in the PCL programming documentation are meant to be compiled with a utility like HP's JetASM before being sent to a printer.
In this way, the Windows printer driver simply passes through GDI commands with very little modification, leading to faster return-to-application times.