What is the VO?

The goal of the Virtual Observatory (VO) is most easily described by analogy with the World Wide Web. When browsing from one hyperlink to another, a user is able to access a huge range of documents. These are constructed by many different people and organisations, and spread all over the world, but to the user they feel as if they are inside her computer. The Web is transparent. The goal of the Virtual Observatory is to achieve the same feeling for astronomical data - that it is all available to explore in a single transparent system.

Like the World Wide Web, the VO is not a fixed system, but rather a way of doing things.

The VO allows astronomers to interrogate multiple data centers in a seamless and transparent way, provides new powerful analysis and visualization tools within that system, and gives data centers a standard framework for publishing and delivering services using their data. This is made possible by standardization of data and metadata, by standardization of data exchange methods, and by the use of a registry, which lists available services and what can be done with them.

The long term vision is not one of a fixed specific software package, but rather one of a framework which enables data centers to provide competing and co-operating data services, and which enables software providers to offer a variety of compatible analysis and visualization tools and user interfaces. The first priority for the VO projects worldwide is to develop the standardized framework, which will allow such creative diversity.