Cambridge courses cover their subjects very broadly in the initial years and then become more specialized and offer a wide range of options as the course progresses.
Most students take courses in one subject area throughout their degree course, following their Part 1 course in a Tripos with Part II in the same Tripos (and remember there is nothing mysterious about the word 'tripos' - it's just the way we refer to the subject areas such as History, Geography, Computer Science, Natural Sciences etc and their examinations). However it is sometimes possible to change Tripos after Part I or Part IA.
Homerton offers opportunities in all of the areas of study provided for by the University, except Veterinary Medicine and Architecture.
If you're not sure about which subject to study, this short film will give you some helpful advice.