If you are a citizen of a European Union country: you do not need a visa.
If you are a citizen of a country which is not a member of the European Union:

For a stay of less than 90 days: the visa you need is a short stay visa known as a ""Schengen visa"".  Some countries do not require this visa. You can view the list here

For a stay of more than 90 days  the visa you need is a long stay visa adapted to the length and purpose of your stay.

For further information: www.diplomatie.gouv.fr