ASP is Microsoft's means of creating dynamic web pages. Web pages break down into two basic types; static or dynamic

In a static web page, the creator of the page uses HTML to build it, then uploads it to the server. When someone visits the page, the same content that the designer created is downloaded to the visitor's computer and displayed in their web browser. A dynamic page differs slighlty. It also sends HTML to the visitor's web browser, but before it does this, it checks to see if there are any instructions it has to carry out first.

These instruction usually consist of filling in a template with an article or the details of a company. The content used to fill in the template is stored in a database. Once the template has been filled in with the details from the database the page is downloaded to the visitor's web browser  in the same way as a static page.

Web sites which use information stored in databases as usually referred to as having a "Front-End" and a "Back-End".

The front-end is the part that we the visitors to that site see. The back-end is the administration area where members of staff can make changes to the web site such as changing prices in a database of products or adding new products.

A distinction is sometimes drawn between as both roles require a different skillset.

An API is an Application Programming Interface, though as is the way with most acronyms, spelling them out makes us none the wiser.

The important bit of this acronym is the "Interface" part, because it describes what an API does. An API exposes part of a programme to another programme. It enables one programmes to ask questions of another programme and receive answers it can understand.

For example, Google Maps is a web site that you may be familiar with. When you enter an address, it will show you a map centred on that address. However, Google Maps also has an API which allows us to place maps on our own web sites. The question that we ask is the computer equivalent of "Can I have a map for these co-ordinates please?". The API returns the information required to build the map and draws it on the page of your web site.

You can use other people's API on your own web site or you could build and API to let other people access your own information and display it on their website.

For example. If you sell widgets on your  you could build an API that exposes some of the information about your stock levels and prices to your business partners.