It is an official document that every country issues to its natural citizens or to those who had become asylee when he/she is a citizen of another country. A passport or any corresponding document is necessary while traveling from one country to another.
The Turkish citizens can contact the General Directorate of Public Security to get detailed information on types of passports, issuance of passports, lost passports and extending passports.www.egm.gov.tr
It is the permission document issued by the representative (consul, embassy, etc.) of the destination country, while traveling from one country to another.
If people intend to pass from one country through another country to a third one and should travel through the customs area of the second country, they require a "Transit Visa" issued by the second country according to the interstates agreements.
A visa for any of the 10 Schengen countries allows you to travel to the other Schengen countries. The customs officers check whether the traveler has activated his/her schengen visa by a visa issued by the consul of the destination country. (The Schengen countries are Germany, Austria, Belgium, France, Netherlands, Italy, Spain, Luxemburg, Portugal and Greece.)
Multiple entrance and leave (valid until the expiry date of the visa).
Single entrance and leave (used only once, second entrance is not allowed even before the expiry date of the visa).
For detailed information: Ministry Foreign Affairs of the Turkish Republicwww.mfa.gov.tr