The shape of the pot bottom can be roughly divided into three types: a sharp bottom, such as a wok; Flat-bottomed, such as rice cookers; A concave bottom, such as a casserole.
Different shapes of pot bottom have different fire distribution: the sharp pot bottom is beneficial to the dispersion of fire and the formation of gradient temperature at the pot bottom, which is suitable for fierce fire; Flat-bottomed firepower is suitable for most situations and is used the most; The fire in the concave bottom is concentrated at the bottom of the pot, which is suitable for slow stewing with small fire.
With the improvement of the manufacturing level of stoves and pots, the distribution of firepower is no longer important. For example, for gas stoves, we don't rely on a sharp-bottomed wok suitable for firewood stoves to disperse firepower, but use a sharp-bottomed wok more, so that ingredients are automatically concentrated at the bottom of the wok; The small burner in the center of the cooker can fully meet the demand of slow stewing.
It is the custom of China people to fry fish in a sharp-bottomed pan. Because of their cooking habits, people in China seldom prepared a few useful flat pots in the past, and deep pots were not convenient for turning fish, so it was normal for woks to be used for frying fish. In European and American cooking habits, "frying" is rarely used, so they are used to frying fish and eggs in a pan.
Actually, the frying pan mentioned by China people should be called frying pan, which is more suitable for "frying".