What are the basic difference between ASP.Net Web applications and Share Point Application

SharePoint

• it's a web site
• SharePoint is actually an ASP.NET application.
•  it's an complete tool, fully ready to use
•  all the authentication/authorization implemented, document management  implemented 
• SharePoint is the common application where a Single web form can be used by everyone and it has the property to differentiate the different user the webform page
• SharePoint is a massive "application platform" -- Intranet Portal, External Website, Collaboration Tool, Business Intelligence Agent, Content Management System, Document Retention System, etc 
• SharePoint / Dynamics CRM 2011 using the underlying application as a framework providing goodies such ad Security, Logging, Workflow, Persistence, File Storage, Alerting, etc.
• SharePoint is often used to store and track electronic documents or images of paper documents
•  Intranet is shared content accessed by members within a single organization. 
•  Extra net is shared content accessed by groups through cross-enterprise boundaries. 
• Internet is global communication accessed through the Web. 

.NET Application

• you can make your own portal with ASP.NET
• asp.net is creating web page and deployed in the server
• .NET" site does not need to have SP installed: just IIS with any required ASP.NET extensions.
• .NET framework  is a toolset that allows you to build applications / website