The 90-Day Non-Immigrant visa is issued to foreigners who wish to enter Thailand for study, business, investment, retirement and other purposes. This type of visa is valid for use for 90 days from the date of issue. The holder of this visa is also given a period of 90 days stay inside Thailand and can be extended for 7 days.
Furthermore, this type of visa grants the holder the option to convert to a 1-Year Non-Immigrant visa stay (i.e. work visa, marriage visa, retirement etc) which can be processed and obtained inside Thailand