Both British and American universities offer Majors/Minors and Joint or Double Degrees.
All of a university's main courses are
Majors. Majors give you Bachelors and all that. Then, there are subjects that you can study
with your Major, as a small part. These courses are
minors.
Say, you want to be a Lawyer. Perhaps you want to work in Europe. You can take Law as a Major (single honours Bachelors, in this example). If your university offers it, you can take a minor course in a european language, such as French. This is how it will appear:
Law (Ba Honours)
with FrenchYou can't take a Minor by itself, and it is not compulsory to have one.
A
Joint Major is when you take two Majors, but you study about 50% of both. The idea is to blend the two Majors together.
A
Double Major is when you take two Majors and you study
everything in those majors.
This should help explain double major and joint majorAlso this.