Write two difference between rapid combustion and spontaneous combustion

Initiation: Rapid combustion is a type of combustion in which a substance reacts with oxygen to produce heat and light quickly. This process requires an external source of heat to start the reaction. On the other hand, spontaneous combustion occurs without any external ignition source. It happens when a material with a low ignition temperature begins to release heat, which may occur as a result of self-heating.

Speed: Rapid combustion, as the name suggests, happens rapidly and produces a large amount of heat and light in a short period of time. Spontaneous combustion, however, is a slow process. It starts with a slow oxidation process, and if the heat produced cannot escape the substance, the temperature of the material rises and can eventually lead to a fire.