If you have an HTML website, it probably uses a very small amount of system resources as it's static, but that isn't the case with dynamic database-driven Internet sites that use PHP scripts and provide you with a lot more capabilities. This type of websites generate load on the website hosting server anytime somebody browses them, due to the fact that the web server needs time to execute the script, to access the database and then to deliver the info requested by the visitor's Internet browser. A popular discussion board, for example, stores all usernames and posts within a database, so some load is created every time a thread is opened or a user looks for a certain name. If a lot of people connect to the forum at the same time, or if every single search involves checking hundreds of thousands of database entries, this can create high load and affect the functionality of the site. In this regard, CPU and MySQL load stats can give you data about the site’s overall performance, as you can compare the numbers with your traffic data to make a decision if the site should be optimized or transferred to a different sort of hosting platform that'll be able to bear the high system load in case the site is really popular.