1, with different parts of speech: fish is a noun, which refers to various fish animals; Fishing can be used as both a verb and a noun.

2, the relationship is different: "fishing" is the production process of fish, not a simple fishing technique. Fish and fish are transformed into each other. With the nourishment of fish, you have the opportunity to learn fishing skills.

3, the structure is different: fish is the upper and lower structure, fishing is the left and right structure.