Because we encounter PHP more and more in the enterprise market, the performance demands of websites we build are becoming ever more challenging. The usefulness of caching is often underestimated by developers (myself included). When using a lightweight framework like Code Igniter it is easy to assume caching is not needed or not necessary; still there are websites where performance optimization is needed and it is important to think about the performance and caching strategy beforehand. When writing the technical specifications for a high performance website the developer needs to be able to make the best choice for optimization.
