Thailand is divided into 75 provinces (76 if you count the special administrative area of Bangkok). These are grouped into 5 groups of provinces (North, North-East, Central, East and South). The capital Bangkok, though not a province but a special administrative area, is usually also included as a 76th province as it is at same administrative level as the other provinces.
Bangkok is both the province with the highest population and the highest population density. The biggest province by area is Nakhon Ratchasima, the smallest Samut Songkhram. Ranong has the lowest population number, while Mae Hong Son has the lowest population density (numbers according to 2000 census).