Welcome to the domain of a Knife Maker in South Africa.
According to Wikipedia a knife is any cutting edge or blade,with or without a handle. Knives were used at least two-and-a-half million years ago. Originally made of rock,flint,and obsidian; knives have evolved in construction as technology has with blades being made from bronze,copper,iron,steel,ceramics, and titanium. 
Many cultures have their unique version of the knife. Due to its role as humankind's first tool, certain cultures have attached spiritual and religious significance to the knife.
Most modern-day knives follow either a fixed-blade or a folding construction style , with blade patterns and styles as varied as their makers and countries of origin.