Post Script vs. PCL print drivers

First, what is the difference between Post Script print drivers and PCL print drivers.

Second, I have users who are trying to print pdf attachments. When ever they try to print the pdf attachments the printer gets an error code of 79.00EF. The printer has to be shut down and turned on again. If I installed Post Script drivers would this enable pdf attachments to be printed without locking up the printer? I appreciate any input/guidance. Thanks

Markus