The Unit describes the properties of objects via three senses: the Distance sense, the Area sense, and the Volume sense.
The Distance sense of the Unit is used to describe the lengths, widths, heights and/or thicknesses of objects. The unit distance, referred to as a linear unit, is defined as the length of an edge of a Tiny Floor.
Sawmills report current Plank Cross Section properties (plank width and thickness) as well as maximum log length and width in terms of linear units.
The Area sense of the Unit is used to describe the size of a surface. The unit area, referred to as a square unit, is defined as the area of a square surface with a side length of 1 linear unit (each face of a Tiny Floor qualifies as such a surface).
The number of swings required to completely chop through a log or plank is directly proportional to its cross-sectional area. For example, if it takes 10 swings with a particular axe to chop through a 1-linear-unit-wide log, it will take 40 swings to chop through a 2-linear-unit-wide log of the same wood type --- this happens because the 2-linear-unit-wide log has a cross-sectional area of (2 * 2 =) 4 square units while the 1-linear-unit-wide log has a cross-sectional area of (1 * 1 =) 1 square unit.
The Volume sense of the Unit is used to describe the amount of space occupied by an object. The unit volume, referred to simply as a unit, is defined as the amount of space occupied by a cube with a side length of 1 unit (a Tiny Floor qualifies as such a cube).
Blueprints report their Wood Required properties in terms of units and are filled as soon as they are in contact with one or more planks with a total volume greater than or equal to the value of this property. Additionally, the amount of Money a player receives by inserting a given log or plank into Wood Dropoff is directly proportional with its volume as well as its wood type.
The unit is the standard measurement used in wood trades between players. Wood prices are often reported on a per-unit basis, allowing prospective buyers to calculate the total price by multiplying the price per unit by the number of units of wood desired.
To create a unit of wood for trading with other players, one must first pass a log or plank of the desired wood through a sawmill with X1 Y1 as its Plank Cross Section settings. Then, they must slice the resulting plank to the correct length of 1 linear unit, which can be achieved by cutting it to match the length of a Tiny Tile blueprint (or, more generally, any object which has a length of exactly 1 linear unit).