@Ozan ******
and
@Jo *********
: there is a single entry 60-days tourist visa, upon entering you get stamped in for a 60-days stay permit. This stay permit can get extended for 30 more days. The tourist visa becomes invalid upon entry. If you arrive without a visa, you do a visa-exempt entry and also get stamped in for a 60-days stay permit, which you can extend for 30 more days on Immigration for 1900 THB