Dynamic pages are the data driven pages which are created depending on the user request. It is created by server-side scripting languages such as php, asp, jsp, perl, cgi and so on. Here in this scripting language it cannot be compiled beforehand, it will be processed by the web servers depending on the user request.
Dynamic URL and dynamic content, this can lead into confusion because they are two separate but related terms. Dynamic content is the information that is delivered to the web browser in a different form than it exists on the server, where as Dynamic URLs, are website addresses that contain (?).Dynamic Urls are the addresses of the dynamic content.
Dynamically generated web pages do not actually exist on the internet until visitors submits a request. Visitor will find their relevant information in a dynamic site using search query. The portion of the link containing the search parameters are called as query string. But the search engine doesn’t know to answer the question, so they get stucked up and stop indexing. Search engines are very much cautious when indexing dynamic pages because they don’t want to get stuck up in an endless loop.