If you have an HTML website, most likely it uses a small amount of resources simply because it is static, but this isn't the case with dynamic database-driven websites that use PHP scripts and offer far more capabilities. Such sites generate load on the hosting server anytime anyone browses them, due to the fact that the web server needs time to execute the script, to access the database and then to provide the data requested by the visitor's web browser. A popular discussion board, for example, stores all usernames and posts in a database, so some load is created every single time a thread is opened or an end user looks for a certain phrase. If lots of people access the forum at the same time, or if every single search involves checking hundreds of thousands of database entries, this can produce high load and affect the functionality of the website. In this regard, CPU and MySQL load statistics can give you information about the site’s overall performance, as you can compare the numbers with your traffic data and see if the site has to be optimized or transferred to a new kind of website hosting platform that'll be able to bear the high system load in the event that the site is popular.