The CPU load is dependent upon the length of time a hosting server spends executing a script whenever a visitor opens a page on a specific script-driven website. Static HTML websites use barely any CPU time, but this is not the case with the far more advanced and functional scripts, that use a database and display dynamic content. The more individuals open this type of a website, the more load will be produced on the web server and if the database is big, the MySQL server shall be loaded as well. An illustration of what may cause high load is a web-based store with a large number of products. If it is popular, plenty of people shall be visiting it concurrently and if they search for items, the entire database containing all the products will also be constantly accessed by the script, which will result in high load. In this light, having CPU and MySQL load stats will give you an idea of how the site is doing, if it needs to be optimized or if you just need a more efficient web hosting solution - if the site is popular and the current setup can't deal with the load.