As we know, matter is anything that has mass and takes up space (has volume).  "Stuff" that fits that definition can come in one of four basic states, or forms, of matter: solid, liquid, gas, or plasma.

Fire, that is the light that is produced during combustion, is not matter as it does not have mass.  Fire is a form of raidiant energy and energy is not matter.  Therefore, fire is none of the possible states of matter.