Blazon = to describe a shield in words using heraldic terms.
Emblazon = to draw or paint a shield from a blazon.
   The simplest type of shield has only one main charge (the "things" on a shield are called charges), so it is blazoned with the color of the field (background), and then the charge and its color.

Colors:
   Gules - bright red
   Azure - royal blue or sky blue (not pastel)
   Vert - emerald green
   Purpure - royal purple
   Sable - black
Metals:
   Or - gold (yellow)
   Argent- silver (white)

   The basic rule is "metal on color, or color on metal, but not metal on metal or color on color". "Proper", means in the most common colors found in nature for that object. The rule "metal on color and color on metal" is not always used when the charge is "proper".
   Animals were shown in certain traditional postures, which were not meant to be realistic pictures of the animals. There were names for the positions in which the animals were shown. Here are some of the most common.
   rampant-standing on hind legs.
   rampant guardant - standing on hind legs, face turned toward viewer.
   passant - walking.
   couchant - lying down.
   sejant - sitting. 
 

vert, a lion rampant or A gold lion in profile standing on his hind legs on a green shield.

   The background of the shield was often divided, and there are names for the common divisions.
 

per bend azure and sable, a lion rampant argent A shield divided diagonally, upper left to lower right, blue on top and black on the bottom, with a silver lion standing on his hind legs.

Vert, a tierce azure, in chief three roses or A shield divided vertically into three parts, the first one blue, the other two green, with three gold roses across the top of the shield.

Sable, a chevron inverted or charged with three mullets (stars) gules Black, with a chevron (an inverted V-shape) on which there are three red stars (the red stars are on the chevron).

   Common divisions of shields are shown below, together with the most common major shapes, termed Ordinaries. Shield divisions do not have to follow the metal/color rule, as they are considered to lie next to each other, not one on top of another. Ordinaries do follow the rule.

Chief	Cross	Saltire	Tierce

Chevron	Chevron Inverted	Per Chevron	Per Chevron Inverted

Pile	Pile Inverted

Bend	Per Bend	Bend wise

Fess	Per Fess	Fess wise

Pale	Per Pale	Pale wise

Pall	Per Pall	Per Pall Inverted

   Sometimes shields were divided into four parts, or quartered, to show the arms inherited from both sides of the family. The upper left quarter is named first, then the right upper quarter, then the two lower quarters in the same order.
 

Quarterly, 1st and 4th, azure, a gryphon or, 2nd and 3rd, argent, a cross moline gules The first quarter and fourth quarters are blue with a gold gryphon, the second and third quarters are white with a red cross with split ends.