Who does not need a visa
Citizens of all countries in the European Union, Switzerland, Iceland, Norway, Croatia, Israel, most North and South American countries, Japan, Australia, New Zealand, and a few other countries require only a valid passport or proof of identity to enter Austria (in some cases, passports that have expired within the last five years are also accepted, as are national ID cards issued by EEA countries and Switzerland).
If in doubt, please make sure to contact the Austrian Consulate or Embassy before your departure. Under the Schengen Treaty, regular passport controls are generally no longer in effect at the borders between Austria, Germany, Italy, Switzerland, Slovakia, Slovenia, the Czech Republic, and Hungary; you must nevertheless carry a valid passport or proof of identity with you when traveling between Schengen countries.
Who needs a visa
Travelers who require a visa can travel to all Schengen states for up to three months with a Schengen visa (visa C: travel visa) which can be issued by every Schengen member state. With a Schengen visa issued by the Republic of Austria, for example, entry is permitted into Germany and Italy and vice versa. The country that represents the visitor's main travel destination is responsible for issuing the visa. In these cases, entry via a different Schengen country than the one that issued the visa is also possible. If there is not a primary destination (e.g. a multi-city trip), the country through which the first entry into the Schengen area occurs is responsible for issuing the visa.
The Schengen area currently consists of Belgium, Denmark, Germany, Estonia, Finland, France, Greece, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Austria, Poland, Portugal, Sweden, Switzerland, Slovakia, Slovenia, Spain, Czech Republic, and Hungary.