The lowest temperature at which a substance catches fire and undergoes combustion liberating heat and light is called ignition temperature.
In other words it is the minimum temperature at which a combustible substance such as air or gas, must be heated up prior to burning in the absence of any source of the heat. This temperature plays a key role in determining the safety criterions for low volatile products such as diesel oil, lubricating oil, and fuel oil.
We have already observed that matchstick gets ignited as soon as we strike it against the matchbox whereas it takes a lot of time to ignite a mosquito repellent.
Similarly kerosene oil does not catch fire on its own at room temperature but as soon as it is heated a little it catches fire. This is because they have different temperature at which they start burning when heat is provided to them.