What is the difference between a cap and a tam?

A cap and a tam are both headgear worn during graduation ceremonies, but they differ in terms of style and purpose. A cap, also known as a mortarboard, is the traditional headpiece most commonly associated with graduation. It consists of a flat square-shaped board with a stiff, short-tasseled top. Caps are typically worn by graduates to symbolize their achievement, with the tassel often hanging on one side. On the other hand, a tam, also referred to as a tam o'shanter, is a soft, round-shaped hat with a slouchy top and no tassel. Tams are often associated with higher academic degrees and are worn by certain graduates or faculty members, depending on the university's traditions. The tam represents the wearer's academic discipline or field of study and is usually made of velvet or a high-quality fabric. Overall, the main differences between a cap and a tam lie in their shape, style, and the specific occasions or degree levels they represent.