* The hot coffee produced a fragrant vapor that filled the air. (Describing steam)
* The magician made the dove disappear in a puff of vapor. (Describing smoke or mist)
* The vapor trails left by the jet planes painted the sky with streaks of color. (Describing condensation)
* The scientist studied the properties of water vapor in the atmosphere. (Describing a scientific concept)
* After the explosion, a thick vapor cloud settled over the city. (Describing a dangerous situation)
As you can see, "vapor" can refer to many things, from steam and smoke to condensation and even dangerous gases. The specific meaning will depend on the context of the sentence.