If you have an HTML site, it probably uses a very small amount of system resources due to the fact that it's static, but this isn't so with dynamic database-driven sites that use PHP scripts and provide way more functions. This sort of websites generate load on the website hosting server each and every time anyone browses them, simply because the web server needs time to execute the script, to access the database and then to supply the information requested by the visitor's browser. A widely used discussion board, for instance, stores all usernames and posts in a database, so some load is produced any time a thread is opened or an end user searches for a certain phrase. If many people connect to the forum simultaneously, or if every single search involves checking a large number of database entries, this can generate high load and affect the functionality of the site. In this regard, CPU and MySQL load data can give you information about the site’s functionality, as you can compare the numbers with your traffic stats to make a decision if the Internet site must be optimized or migrated to another kind of web hosting platform that'll be able to bear the high system load in the event that the website is very popular.