Updated: Apr 1, 2019
On the Encyclopaedia Britannica, best describes heraldry as:
Heraldry, the science and the art that deal with the use, display, and regulation of hereditary symbols employed to distinguish individuals, armies, institutions, and corporations. Those symbols, which originated as identification devices on flags and shields, are called armorial bearings. Strictly defined, heraldry denotes that which pertains to the office and duty of a herald; that part of his work dealing with armorial bearings is properly termed armory.
I then looked into the meaning of some of the symbols used in crests
After speaking to my course leader, he recommended I take a look at the 'Sigils of the houses of Westeros' poster. This gave me another angle to look at the designs of crests.
I discovered that this poster was designed by a guy called Darrin Crescenzi, and it is his own interpretation of the houses from the TV show 'Games of Thrones'. Each crest is completely different from the last one and Crescezi has used limited amount of images.
Crest designs from the Harry Potter films.