Your short-stay visa does not automatically entitle you to enter the Schengen area. At border or during other controls you may, for instance, have to provide information on your means of support, how long you intend to stay in the Schengen State, and why you are visiting the Schengen State.
In some cases, such checks may result in a refusal for the visa holder to enter the Schengen State or the Schengen area.
It is therefore recommended that you carry with you copies of the documents which you presented when you applied for the visa (e.g. letters of invitation, travel confirmations, other documents stating the purpose of your stay). This will help to make the border control procedure easier and avoid delays at the border.
The definition of short stay of non-EU citizens in the Schengen area is "90 days in any 180 days period" The short-stay calculator can be used for calculating the period of allowed stay. The user's guide contains information on these rules, the use of the calculator and practical examples.