CUPS is the software you use to print from applications like word processors, email readers, photo editors, and web browsers. It converts the page descriptions produced by your application (put a paragraph here, draw a line there, and so forth) into something your printer can understand and then sends the information to the printer for printing.
# Manage printers through CUPS:
# http://localhost:631 (in web browser)
# Print file from command line
lp myfile.txt
# Display print queue
lpq
# Remove print job from queue
lprm 545
or
lprm -
# Print log location
/var/log/cups
# Reject new jobs
cupsreject printername
# Accept new jobs
cupsaccept printername