The CPU load depends upon the time period a server spends executing a script each time a visitor opens a webpage on a certain script-driven website. Static HTML websites use barely any CPU time, but this is not the situation with the much more advanced and functional scripts, which use a database and display dynamic content. The more individuals open this sort of an Internet site, the more load shall be generated on the web server and if the database is big, the MySQL server shall be loaded also. An illustration of what could cause high load is a web-based store with tens of thousands of products. If it's popular, plenty of people will be visiting it all at once and if they search for items, the entire database which contains all of the products will 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 Internet site is doing, if it needs to be optimized or if you just need a more efficient hosting solution - if the site is very popular and the current setup can't handle the load.