What does mass, volume, and temperature measure?

The metric system measures mass in grams or kilograms, distance in meters or kilometers, and volume in liters. It measures temperature in Kelvin or Celsius degrees instead of the Fahrenheit degrees used in the imperial system.

The mass of a body is a measure of the resistance against a change of motion state of the body itself. That's why they usually call it "inertial mass" and is somehow an exclusive property that doesn't depend on "where" the body is in the space.

The volume of a body literally the amount of three-dimensional space that the body occupies.

The temperature of a body is a measure of the kinetic energy that the body has. The more the atoms of the body are moving, the hotter the body will be. Absolute zero (i. e. 0° K) is a state where all of the atoms of a body are motionless.

With reference to the international system of units, mass is measured in kilograms, volume in cubic metres and temperature in Kelvin.