Dry Bulb Temperature Shown as vertical brown lines and depicts standard temperature measured by a thermometer.

Wet Bulb Temperature Shown as shallower diagonal "reddish" lines associated with the water content in the air.

Specific Volume Is the volume that a certain weight of air occupies under specific conditions (ft³/lb). Shown as the steeper diagonal purple lines from 12.5 to 15.

Relative Humidity Shown in percentages the amount of water air can hold at a certain temperature. Warm air can hold more water than cold air.

Absolute Humidity aka humidity ratio is shown as the horizontal lines. It iis the easure of water vapor in the air Expressed in grams of moisture per cubic meter of air (g/m3).

Enthalpy Measure of heat energy in the air due to sensible and latent heat. Sensible heat is the temperature in the air Latent heat is the moisture in the air. In units of Btu/lb and is show on the diagonal scale to the left.

Dew point Temperature Is the temperature at which water will begin to condense out of moist air. I is represented on the 100% humidity line (humidity lines are the green curves).

Vapor Pressure Do not worry about Vapor pressure.