In US colleges and universities, most courses are numbered. They can begin with the number 1 (French 1: introduction to French) or with 101 (French 101: introduction to French). So, a course numbered 101 is generally understood to be an introductory-level course, a course for beginners.
The first digit of the course number refers to the level (1=1st year, 2=2nd year, etc.), and "Subject 101" would be the number one 1st year course in that subject, an introductory overview of the subject. In this case the subject being introduced for the beginner is "Financial Statements".