Your size is defined by your race, with some races being able to choose between two or more sizes. Your size determines several of your statistics, as shown in the Creature Size table below.
A creature has a carrying capacity in pounds equal to its Strength score multiplied by the number listed in the Creature Size table.
A monster has a number of hit points equal to a roll of its hit die. This method of determining hit points is exclusive to monsters or NPCs that lack class levels.
You must eat and drink a minimum amount of food (in pounds) and water (in gallons) each day.
Your reach determines how far (in feet) you can attack, grapple, grip, hold, or touch a target.
Your space is the area (in feet) that you effectively control, not an expression of your physical dimension.
Your movement speed determines how far you can move in a round (in feet), in a minute (in feet), and in an hour (in miles). Some features might grant you different types of speed, as well as increase or decrease your speed.
You have a +5 bonus to your passive Perception and passive Stealth scores against creatures for each size below yours, and creatures one size larger than you have a −5 penalty to their passive Perception and passive Stealth scores for each size above yours.