Academic gown in the context of "Tudor bonnet"

Postgraduate education, graduate education, or graduate school consists of academic or professional degrees, certificates, diplomas, or other qualifications usually pursued by post-secondary students who have earned an undergraduate (bachelor's) degree.

The organization and structure of postgraduate education varies in different countries, as well as in different institutions within countries. The term "graduate school" or "grad school" is typically used in North America, while "postgraduate" is more common in the rest of the English-speaking world.

The square academic cap, graduate cap, cap, mortarboard (because of its similarity in appearance to the mortarboard used by brickmasons to hold mortar), or Oxford cap is an item of academic dress consisting of a horizontal square board fixed upon a skull-cap, with a tassel attached to the centre. In the UK and the US, it is commonly referred to informally in conjunction with an academic gown as a "cap and gown". It is also sometimes termed a square, trencher, or corner-cap. The adjective academical is also used.

In previous centuries, academic dress was the everyday clothing of all students and faculty. The cap, together with the gown and sometimes a hood, now form the customary uniform of a university graduate in many parts of the world, following a British model. In other countries, especially the United States, mortarboards are only worn during the commencement ceremony itself.