The CPU load depends on the amount of time a hosting server spends executing a script every time a visitor opens a page on a certain script-driven website. Static HTML websites use hardly any CPU time, but this isn't the situation with the considerably more complex and functional scripts, that use a database and display dynamic content. The more people open this sort of an Internet site, the more load will be generated on the server and if the database is big, the MySQL server shall be loaded as well. A good example of what may cause high load is an online store with a large number of products. If it's popular, plenty of people will be exploring it at the same time and if they search for items, the whole database which contains all the products shall also be constantly accessed by the script, which will result in high load. In this light, having CPU and MySQL load stats will offer you an idea of how the website is doing, if it has to be optimized or if you simply just need a more potent web hosting solution - if the Internet site is very popular and the established setup can't deal with the load.