⟩ What is the difference between a site and a web?
A collection of sites along with the top level site is known as a single site collection in Sharepoint. While creating a new Web Application, one has to follow creating a site collection to specify the content of the web application. A web application can thus even contain thousands of site collections. The web application is needed to host those site collections. Web application is the logical & physical partition/container within IIS to create portals.