The below pictorial view depicts the logical architecture of a SharePoint Application:

Below is given some important points to remember about SharePoint Applications:

  • Each SharePoint web application can have multiple content databases.
  • Each content database can have multiple site collections.
  • A site collection is a set of Web sites that have the same owner and share administration settings.
  • Each site collection contains a top-level Web site and can contain one or more sub sites.
  • Each site (top-level site and sub sites) within site collection can have its own document libraries and custom lists.
  • The Page Layouts, Master Pages, and Web Parts can be shared only within a site collection.
  • Sub sites within a site collection can inherit permissions from the top-level site.
  • Site collections cannot inherit permissions from other site collections.
  • There is no built-in navigation from one site collection to another.
  • SharePoint search provides search results only within a single site collection and it does not include results across multiple site collections.
  • URL of the web application for different site collections will be like below:
    Site Collection1: http://servername/sites/sitecollection1
    Site Collection2: http://servername/sites/sitecollection2