Active Server Pages (ASP pages)
Definition - What does Active Server Pages (ASP pages) mean?
Active Server Pages (also known as ASP or classic ASP) is Microsoft’s first server-side script engine that enabled dynamically-generated web pages. While the initial release was an add-on to the Internet Information Services (IIS) component of Windows NT 4.0, it was later incorporated into the Windows Server operating system.
ASP employs server-side scripting to dynamically produce web pages based on a specific request from the client. The result is a HTML webpage sent back to the client for display. VBScript is the default scripting language used for writing ASP, although other scripting languages can be used.
Techopedia explains Active Server Pages (ASP pages)
ASP was Microsoft’ alternative to Common Gateway Interface (CGI) scripts and Java Server Pages (JSPs), both intended to allow clients to interact with server-side databases and enterprise services. ASP has gone through three major releases: ASP 1.0 in 1996 (included with IIS 3.0), ASP 2.0 in 1997 (IIS 4.0) and ASP 3.0 in 2000 (IIS 5.0). ASP 3.0 becomes part of IIS 6.0 on Windows Server 2003 and part of IIS 7.0 on Windows Server 2008.
ASP is now obsolete and replaced with ASP.NET. Though, ASP.NET is not strictly an enhanced version of ASP; the two technologies have completely different underlying implementations. ASP.NET is a compiled language and relies on the .NET Framework, while ASP is strictly an interpreted language. As with any older technology, you can certainly find ASP in production, but you'd be hard-pressed to make the case to use it for a new project.