In the past couple of weeks I had to implement parallel processing with PHP twice. Since it was very effective I thought I'd share it with you all.

The idea of parallel processing is when you take an atomic transaction or operation called a 'process' and run a couple of those at the same time. Many programming languages support this via threading or forking. Since most computers have multi core CPU's and can handle multiple processes at the same time your application can benefit from having multiple transactions running at once.