Every framework has its own directory structure. Some of them may be similar to other ones. For example, Laravel looks similar to Symfony, since it’s based on Symfony framework, but on the other hand, CodeIgniter does not look similar to any of the two I mention above.
Frameworks are a powerful tool for quickly building web applications. Learning how to use frameworks will help you to build your projects better and faster. One of the most popular PHP frameworks is called Symfony, which is known to be the hardest to learn from all others PHP frameworks.