This can be a visa (tourist visa for 60 days or non-immigrant visa for 90 days) issued by a Thai Embassy or Consulate outside of Thailand. You can also obtain a temporary stay with under the Visa Exemption Rule (VER). This allows citizens of 41 countries* permission to enter the Kingdom for a limited period of time (up to 30 days depending on the nationality) in accordance with Thai Immigration Law. This is commonly referred to as a 30-day stamp.