There is a lot of argument whether Redis or Memcache is better, though as the benchmarks show they perform pretty much on par with each other for basic operations. Redis has more features than Memcache has, such as in-memory and disk persistence, atomic commands and transactions, and not logging every change to disk but rather server-side data structures instead. In this article we'll take a look at some of the basic but powerful commands that Redis has to offer using the Predis library.
He helps you get a local redis server up and running and includes a link to the repository for the latest version of the Predis library. Some sample code is provided showing how to connect to the server, push data into a key/value combination, get the value back out, increment it and check to see if it exists. He also talks about some of the available data types Redis provides and a few other more complex operations you can perform on things other than strings.