Basicly there are 3 types of work permits in Turkey.
Fixed Term Work Permit (Aka Temporary)
According to the International Workforce Law No. 6735, which was published in the Official Gazette dated 13/8/2016 and numbered 29800, the work permit in a certain workplace belonging to a real or legal person or public institution or organization, that it does not exceed the duration of the employment or service contract. This type of work permit is given maximum of one year at the first application.
However the foreigner is granted a maximum of two years in the first extension application and up to three years in the subsequent extension applications in case application is sent by the same employer. However, applications made to work with a different employer are considered under the first paragraph of Article 7.
Indefinite Work Permit
The foreigners with long-term residence permit or at least eight years of legal work permit in Turkey can apply for permission to work indefinitely.
The foreginers who have indefinite work permit have almost the same rights with Turkish citizen but right to vote and stand for election. They dont also have obligation for military service.
Indipendent Work Permit
Independent work permits may be granted to professionals, who meet the special conditions specified in laws.
In the evaluation of the independent work permit, the education level, professional experience, and the contribution of foreigners to science and technology are taken into account. Beside Ministry of Labor consider that the impact of foreign investment in Turkey’s economy and employment.
Independent work permit is issued for a period not indefinite.