An ITIN (Individual Taxpayer Identification Number, sometimes called a PIN, Tax ID or Taxpayer ID) will serve as your identification number for filing your tax returns. If you do not qualify for an SSN, you will need to apply for an ITIN.
Active Server Page Extended ASP.NET script. An aspx file extension is associated with Active Server Page Extended format used by Internet Information Services (IIS) web server with server side scripting language ASP.NET used to dynamically generate websites. Generated output from an .aspx page in your browser is common html page.
ASP.NET is an open-source server-side web application framework designed for web development to produce dynamic web pages. It was developed by Microsoft to allow programmers to build dynamic web sites, web applications and web services.