The English word for "seaweed" is "seaweed", and seaweed is a type of marine organism found in waters around the globe in a wide variety of environments, including estuaries, coasts, and the deep sea. Generally speaking, seaweeds are soft-bodied plants without rhizomes that can grow to long lengths and stand on the seafloor.

Seaweeds are usually categorized into three groups: red algae, brown algae, and green algae. Red algae belong to the most diverse group and are found mainly on shallow shores, while brown algae are found mainly in deeper oceans and also include coralline algae. Green algae, like red algae, grow mainly in shallow seas and areas such as estuaries and lakes, and can break down harmful nitrogen compounds.

Seaweed, in addition to its many uses in areas such as environmental protection and gastronomy, provides the oceans with an abundance of nutrients and oxygen, as well as being a key link in the foundation of organisms and biodiversity.

In terms of food, seaweed is a traditional food in many countries and regions such as Scandinavia, Japan and Korea, and April's 1st Day is a traditional Japanese festival where people enjoy seaweed dishes called "Seaweed Day". In addition, seaweed is a popular health food, rich in nutrients such as protein, carbohydrates and vitamins. It is also an increasingly popular ingredient in the health food market.

In short, "seaweed" is the English term for a wide range of marine organisms, including red algae, brown algae and green algae, which, in addition to its high value in food, is also an important part of the marine environment organisms and biodiversity conservation.