Seaweed is seaweed; but nori is not all seaweed. Rhodophyta, Rhodophyceae. The algae are purple or red, and are composed of a single or two layers of cells, and are leaf-shaped, heart-shaped, ribbon-shaped, etc. The rhizome-like anchors in the lower part of the nori are attached to the rocks. It can reach 20-30 cm in height. It is dioecious and has a complicated reproductive process. In 1955, Chinese scientists first clarified the life history of Porphyra, which consists of three stages: Porphyra, filaments, and small Porphyra. The main components of seaweed are about 50% carbohydrates, about 30% crude protein, rich in vitamins A, B, and C, and contain iodine, phosphorus, calcium, etc. It is a commonly used food in my country and is distributed along the coast of my country, mainly along the coast of Jiangsu. There are two types of seaweed sold on the market, one is grilled seaweed (roasted seaweed) used for making rice sushi dishes, and the other is called "instant seasoned seaweed". Their raw materials are all seaweed. Edit this paragraph Classification of seaweed 1. Classified according to processing method Dried seaweed: Seaweed that has been processed once. It is generally used in food processing and simple rice wrapping, and can also be eaten directly. For example, the more common ones in China are: golden cherry blossom seal, Korean seaweed, etc. Seaweed Grilled seaweed: The finished product of dried seaweed after secondary deep processing. It is generally used in sushi dishes, food processing, etc., and can also be eaten directly. Nothing is added during the entire process, it is 100 pure natural. For example, the more common ones in China: roasted seaweed with golden seal, etc. Ajifu seaweed: Domestically known as seasoned seaweed, dried seaweed is a finished product after secondary deep processing. (Seasoning liquid is added during the processing) It is generally used as snack food and eaten directly. Such as the more common ones in China: good times, wave power, etc. 2. According to the quality of seaweed, when classifying the quality of seaweed in the industry, it is generally divided into five grades: special, A, B, C, and D (special gold, silver, blue and green). Special grade is the best grade, with the best color and taste; it is generally used for export and domestic high-end restaurants. The price is naturally quite high. It is rarely sold in China. Among the common types of seaweed used for sushi in China, C and D are generally the most common ones. When distinguishing common grades in the domestic market, they are generally identified through packaging. The same series of seaweed will have different packaging colors; the different colors of gold, silver, blue and green packaging of standard seaweed companies correspond to different grades of ABCD. It is recommended to consult carefully when purchasing. Recommend products from regular manufacturers. Explanation: The four grades of Sakura, Pine, Bamboo and Plum respectively correspond to the domestic ABCD, which is the definition of seaweed grade by the Japanese Nori Association. It is the most stringent and rigorous classification level for seaweed grade definition in Japan; it is the general standard for Japanese sushi seaweed. The highest domestic seaweed grading standard mainly refers to the standards of the Seaweed Association, which is the most detailed and strict seaweed grading standard in the country.