转一个spooling的解释: Acronym for simultaneous peripheral
operations on-line, spooling refers to putting jobs in a buffer, a
special area in memory or on a disk where a device can access them
when it is ready. Spooling is useful because devices access dataat
different rates. The buffer provides a waiting station where data can
rest while the slower device catches up. The most common spooling
application is print spooling. In print spooling, documents are loaded
into a buffer (usually an area on a disk), and then the printer pulls
them off the buffer at its own rate. Because the documents are in a
buffer where they can be accessed by the printer, you can perform
other operations on the computer while the printing takes place in the
background. Spooling also lets you place a number of print jobs on a
queueinstead of waiting for each one to finish before specifying the
next one.