Whenever a visitor opens your Internet site, the browser sends a request to the server, which in turn executes it and supplies the desired information as a response. A simple HTML Internet site uses minimal system resources due to the fact that it is static, but database-driven platforms are more demanding and use far more processing time. Every page which is served creates 2 types of load - CPU load, which depends on the length of time the web server spends executing a specific script; and MySQL load, which depends on the amount of database queries created by the script while the client browses the site. Bigger load shall be generated if a whole lot of people surf a certain site concurrently or if many database calls are made at the same time. 2 good examples are a discussion board with a huge number of users or an online store where a client enters a term in a search box and tens of thousands of items are searched. Having thorough data about the load your site generates will help you improve the content or see if it is time to switch to a more powerful type of website hosting service, if the site is simply getting quite popular.