A Schengen Visa will allow the holder to remain and travel in one or more of the Schengen states for up to 90 days in a six month period. A Schengen airport transit visa allows the holder to pass through any airport in the Schengen area en route elsewhere. Citizens of countries that are required to hold a Schengen Visa must apply for a transit visa even if they are to remain airside. If you would like to spend longer than 90 days in the Schengen area, then a Schengen Visa will not be appropriate. You will have to contact the embassy or consulate of the country where you will be spending the majority of your time.