Algae are not plants, although they do use chlorophyll for photosynthesis, and they do have plant-like cell walls.  However, seaweeds have no root system or internal vascular systems; nor do they have seeds or flowers.

It can be divided into 4 groups based on the color.

1. BLUE-GREEN ALGAE : This algae is mostly found. It is on the land and in the water. It can be grown in the hot weather (in the hot spring) and in the cold weather (North pole and South pole). This algae can be dried for food and it is very popular for Eastern Asian people such as Japanese, Korean, and Chinese. In addition, this algae has been produced to the seaweed pill especially for Chlorella and Spirulina.

2. GREEN ALGAE : It can be grown in the fresh water and the sea but it is not be resistance in the environment like the Blue-Green Algae. Shape and size is based on the location. 

3. BROWN ALGAE : It is the algae found in the cold weather such as the coastline of Atlantic and Pacific Ocean and in the warm weather such as in the Gulf of Thailand. It has beautiful color and the size is quite big. This type of algae has many benefits such as LAMINARIA SP. or Kombu which used for doing the Dashi stock in Japan and Undaria or Wakame which is always put in the Japanese soup. Apart from food, this algae is extracted for industrial usage and it can be extracted "ALGIN" which is one of the important ingredient of Kelp Noodle.

4. RED ALGAE : It can be grown in the cold fresh water and in the sea(both in the cold and warm area).This type of algae has many benefits such as PORPHYRA SP.  which is Nori. The Japanese people used nori for sushi dishes. And the Chinese people also used this type of algae in the clear soup. In addition, the coating substance on this algae  called CARRHAGEENIN is used for Agar in the many industry such as Canned Industry, Sweet and Bakery Industry, and Cosmetics Industry.