The CPU load depends upon the time a server spends executing a script each time a visitor opens a page on a particular script-driven site. Static HTML Internet sites use barely any CPU time, but it is not the case with the much more complex and functional scripts, that use a database and display dynamic content. The more customers open such a website, the more load will be generated on the web server and if the database is large, the MySQL server shall be loaded as well. An example of what could cause high load is an online store with thousands of products. If it's popular, plenty of people shall be visiting it at the same time and if they seek out items, the whole database that contains all of the products will also be continuously accessed by the script, which will result 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 needs to be optimized or if you simply just need a more powerful web hosting solution - if the Internet site is very popular and the current setup cannot handle the load.