1) Loading a reel 2) Unwinding 
In computing, SPOOL is an acronym for simultaneous peripheral operations on-line. It is a type of buffering. The most common spooling application is print spooling, which places a task (or `print job`) into a queue for extended or later processing. ==Origin of the term== According to Tanenbaum, `SPOOL` is an acronym for simultaneous peripheral...
• (p. pr. & vb. n.) of Spool
Sending a print job to a print queue, details ...
In computing, the process in which information to be printed is stored temporarily in a file, the printing being carried out later. It is used to prevent a relatively slow printer from holding up the system at critical times, and to enable several computers or programs to share one printer