The CPU load depends upon the time a web server spends executing a script whenever a visitor opens a page on a given script-driven Internet site. Static HTML sites use barely any CPU time, but this is not so with the considerably more advanced and functional scripts, that use a database and display dynamic content. The more customers open this kind of a site, the more load shall be generated on the hosting server and if the database is very large, the MySQL server will be loaded too. An example of what can cause high load is an online store with a large number of products. If it's popular, a lot of people shall be browsing it concurrently and if they look for items, the whole database which contains all the products shall also be constantly accessed by the script, resulting in high load. In this light, having CPU and MySQL load stats will provide you with an idea of how the site is doing, if it has to be optimized or if you just need a more effective website hosting solution - if the Internet site is very popular and the current setup cannot deal with the load.