If I find a FIG I want to register for, do I have to take all of the courses in it?

Yes! A FIG is a package deal. However, some FIGs are standalone classes. 

FIGs are great because they combine courses that show you different perspectives of a common field of study.

For example the FIG H5 has a CSE and GWSS. We have a shortage of women in the stem field, how can taking this class coupled with computer science broaden your understanding of that subject?

Or a FIG with CHEM 142 (many pre-med majors) linked with a sociology course on health disparities or with one of the public health courses – allows you to take a look at different aspects of the medical field. You gain exposure to a subject from varying disciplines and areas of knowledge.