ISAPI

Internet Server Application Programming Interface (ISAPI), 

2 Component (extensions and filters) must compiled into DLL 

• ISAPI extensions
• Called from qualified request to IIS. (URL, POST [Submit Method]) 
• run on IIS, it has access to all functionality in IIS.
• Client can access ISAPI extensions in static HTML or certain file extensions can mapped to be handled by ISAPI extension.

• ISAPI filters
• Called from all request to IIS.
• Used to enhance the functionality by IIS.
• Run on IIS Server and filter every request until they find one they need to process.
• Filter can programmed to examine and modify both incoming and outgoing streams of data. (logging)
• Change request data (URL or headers) send by client.
• Control physical file get mapped to the URL,
• Control Username and password (authentication)
• Change response 
• Encryption and decryption.

Membership

Run below to create a asp.net membership DB

cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319
aspnet_regsql.exe -S LT-OBY-MY -U sa -P p@ssw0rd -A all -d SecurityTutorials

IIS App

Site

• Container for application and virtual directory.
• Binding protocol : protocol communication between server and client. (HTTP / HTTPS)
• Binding Information : combination IP address, port and optional host header.

Application

• Run inside that 'folder'.
• Standalone application. Own Session state and Application State.
• Can run in different App Pool with different .NET version.

Virtual Directory

• Link to a physical folder on the server
• Point to different phyical path into that application. (e.g. image folder)
• only run in DefaultAppPool