How fire can be useful?

Fire is used for cooking, to keep warm and to melt something, heat something up or germinate seeds

there are different ways it can be used. someone could cook with it or keep warm. There are many other ways t use it to such as use it as a light source or something that has no use. Some people use it to light cigarettes.

Fire is the result of rapid oxidization of a material that releases light and heat.

heat and light then cooking, protection

the use of fire is heat which you can use to cook, keep warm and melt things. fire also produces light.