Bachelor's degree
Until the 19th century, a bachelor's degree represented the first degree in a particular faculty, with Arts representing undergraduate study, thus the Bachelor of Civil Law (BCL) at Oxford and the Bachelor of Laws (LLB) at Cambridge, for example, were postgraduate degrees. Vestiges of this system still remain in the ancient universities, with Oxford and Cambridge awarding BAs for undergraduate degrees in both arts and sciences (although both award undergraduate BTh degrees through associated theological colleges, and Oxford awards BFA degrees in addition to the BA) and defining other bachelor's degrees (e.g. BPhil, BCL) as postgraduate awards equivalent to master's degrees, although many postgraduate bachelor's degrees have now been replaced by equivalent master's degrees (e.g. LLM for the LLB at Cambridge and MSc for the BSc at Oxford). The same historical usage of indicating an undergraduate degree by it being in the faculty of arts rather than being a bachelor's degree gives rise to the Oxbridge MA and the Scottish MA).
Academic dress of the University of Cambridge
A graduand (someone about to be presented for a degree) wears the full Cambridge academic dress of the highest status degree that they already hold. Graduands who do not already hold a Cambridge degree wear the gown appropriate to their status in the University, along with hood of the degree to which they are about to be admitted. Undergraduates, who do not yet hold a degree, wear their undergraduate gown, with the hood of the degree that they are about to receive. Thus, for example, an undergraduate graduating to a BA degree wears an undergraduate gown and a BA hood. A holder of a BA from Cambridge graduating to a PhD wears both a BA hood and gown, whereas a graduate of another university graduating to a PhD wears a BA or MA status gown and PhD hood.