I saw a couple of questions dealing with those. Here and here. What exactly are post-processing and post-hooking? And what are they used for?
processing - do some manipulation of data. post-processing simply means to do additional processing after some other processing has been performed. e.g. a bakery will process wheat into bread. You then post-process that bread into a sandwich.
post-hooking - hooking is a one way of saying you're inserting some code into a processing sequence, or intercepting execution at some point in the processing sequence. post-hook simply means you're inserting code to run AFTER a certain operation. pre-hooking would be to execute your code before the operation. e.g. an anti-virus scanner would pre- and post-hook various file system operations, to cache bad stuff before it's written to disk, as well as trap events like "download complete" so it can start scanning the downloaded file.