The Virtual Observatory Data, Standards and Tools a technical - user point of view

In 2002 the International Virtual Observatory Alliance (IVOA) has been created in order to gather efforts on data standardization and dissemination. Since then, the virtual Observatory allowed to spread validated data all over the world and to use data from everywhere from earth. From the standards definitions to development of tools, developers have set up a technical infrastructure used by astronomers to easily search for data and make science with all available products, more tools and more confidence on the quality of data. The goal of this review is to present the state of the art of the VO data, standards and tools. This review focuses on basic astronomer's questions : what kind of data are accessible, how to deal with these data and how to use them.