What is the difference between an degree and a Bachelor degree?

There's no difference; a Bachelor's degree is a type of degree. "Degree" is the general term, while "Bachelor's degree" specifies a particular level of degree. A Bachelor's degree is an undergraduate degree, typically requiring four years of study after high school. There are also other types of degrees, such as Master's degrees (graduate), Doctoral degrees (graduate), and Associate degrees (undergraduate, typically two years).