WordPress is one of the greatest and simplest tools for bloggers today. WordPress uses PHP and thats great, but can at times not so great too. Why so? Receiving a lot of traffic over the period of a day is generally not an issue, however it can be an issue when you start getting a huge amount of traffic that is coming all at once. Unlike normal html webpages, PHP pages are dynamically generated. This means the server frequently re-compiles each page before displaying it to each visitor. This consumes more CPU than a standard webpage, so very popular blogs can quickly consume all available processor time.
Making Things Better
One of the best ways to combat against unnecessary recompiling of php pages (and thus greatly reduce cpu use) is to install and activate the WordPress Super Cache plugin. A cache is a temporary storage place for frequently or recently accessed data, and this is exactly what this plugin is designed to do. It takes the dynamic content in the form of php pages, and presents the results using low-overhead, generally static pages.
I think anyone that installs WordPress should always get this plugin no matter who you are. For the simple fact that when blogging, you may hit a subject or post something that catches on rather fast with social media based websites. The Super Cache plugin is based on the original cache plugin which was created by Ricardo Granada, and is just an overall solid wordpress plugin that is in my top ten favorites. Whats so great about the new over the old?
Difference Between Old and New
The larger difference between the original WordPress Cache plugin and the WP Super Cache is that the original, required manual work for whichever page you wanted to be cached, whereas the Super Cache is automatic. Keep in mind this plugin is not the solution to all your WordPress problems, but it will make a major difference when you are receiving larger amounts of traffic, especially in a shorter period of time than normal.
I would highly recommend that you would read thoroughly over the guide to this plugin to understand what it is intended for. You can read about and install the WP Super Cache plugin HERE.