The following are some key words and definitions that you may find useful:

CUBIC FOOT:  Unit of measure used to figure volume of concrete to fill forms etc.
CUBIC FOOT = 12”x12”x12” 

CUBIC YARD: Unit of measure used to figure volume of loam, gravel, sawdust, shavings, chips and bark mulch.
CUBIC YARD = 3’x3’x3’ or 27 cu. Ft.

CORD: Unit of measure used to figure volume of firewood and pulpwood
1 CORD = 4’x4’x8’ or 128 cubic feet

EXPOSURE: This measurement is what part of a shingle or clap board is “ to the weather”. Used to figure the amount of product used to cover a square (10x10 area) example 1/2x6 bevel siding has @ 4” exposure.12” divided by 4= 3.3 Lineal feet of 1/2x6 clapboard needed to cover 1 square foot. 

LINEAL FOOT: A one foot (12”) length of any size product nominal size versus actual finish size. The finish size is usually different after planing. Example: a 2x4 is finished to 1-1/2 ”x 3-1/2“  

SQUARE FOOT: A unit of area measurement equal to a square 12” on each side.
SQUARE FOOT= L’X W’= number of square feet. 

BOARD FOOT: The basic unit of measurement for lumber. One board foot is equal to a 1” board 12” in width and 1 foot in length.
BOARD FOOT= width x length divided by 12 

SQUARE: A quantity of shingles, shakes or bevel siding sufficient to cover 100 square feet of area; the basic sales units of shingles, shakes and bevel siding.
SQUARE= length x width divided by 100= number of squares. 

D4S: Planed  (Dressed) 4 sides smooth with square edge. 

S2S: Surface (Planed 2 sides)

KD: Kiln dried lumber is placed into a kiln and dried to a desired moisture content furniture 6-8% general woodwork 8-12% framing no more than 19%. 

LIVE LOAD and DEAD LOAD: Factors that help determine structural lumber sizes in a construction project live load= items placed on floor (furniture etc.) or on a roof (snow). 

DEAD LOAD: Weight of actual construction materials both are in pounds per square foot
DEAD LOAD:  Example 50/10= 50 lb. live load 10 lb. dead load.