Generally, the amount of water vapor that a place or volume can hold at a certain temperature, does not contain that amount of water vapor. Relatively less than the capacity. As the temperature increases, this capacity increases, and as the temperature decreases, the water vapor capacity decreases. If this is the case, the water vapor holding capacity of the place is equal to the amount of water vapor there is, then we can say that the place is saturated with water vapor.
Now if we consider an enclosed volume, it does not contain the amount of water vapor it can hold at a given temperature. There is rather less. Now if we lower the temperature of that place, its water vapor holding capacity will also decrease. To reduce the temperature, we will set the temperature of the space at a temperature when the water vapor holding capacity of the space is equal to the water vapor present in it. We call this temperature the dew point of that place.
That is, the temperature at which a place is saturated with water vapor present in it is the dew point of that place. So dew point is the name of a particular temperature.