Web apps are one example of a dynamic website. Take Twitter, for example: when you log in, it shows you material tailored to your interests. Dynamic sites are tremendously powerful, but they are also more difficult to maintain.
A dynamic web application generates pages/data in real time, and a response is triggered from the server end and sent to the client end based on the request (your end). The client-side code will take the appropriate action based on the response. Example: On twitter when you click on follow.
Static sites are frequently referred to as websites, whereas dynamic sites are referred to as web apps. Facebook, for example, is both a website and a web application. A simple website for a business, on the other hand, is not a web application. The most basic type of website is a static site, which is also the easiest to design.
Google constantly adjusts search results to reflect current content, particularly for real-time events. With each page refresh, a search query for news and current events may yield significantly different results.
Wikibooks, Wikipedia, and blog portals are examples of dynamic websites. They enable the server-side to use custom templates and actions, such as logging and adding new data.