The first thing we need to recognise is that there is a key difference between a static and a dynamic website. This website for example is a static website, the files are created, uploaded and there is nothing dynamic about it - there is no database, there is no user input to how the page is displayed and the information is received by the website viewer.
A static website has to be changed using code such as HTML and CSS, the content is hardcoded and usually only a website developer can make changes to the content, this includes text, images and anything else which is on display for visitors to see.
Once the changes are made the developer will upload the content back to the where the websites files are hosted and the changes will be made public, for the world to see online.
We can say in this case that the web pages are delivered to the viewers web browser exactly as they are stored.
A dynamic website has content generated on the fly, depending on user input and other influencing factors.
Different technologies are usually used when producing a dynamic website although the gap between these technologies is closing as of recent years.
An example of a dynamic website may be a booking system where the system will select data from a database and display this on the screen - allowing the user to page through this data. The dynamic part of this is the data which changes, the page may remain the same except for one area of information.