---Coped from Quroa written by an employee of UIUC in 2018 and updated later:
There are nine different computer science majors at Illinois: Engineering CS, Mathematics & CS, Statistics & CS, CS+Anthropology, CS+Astronomy, CS+Chemistry, CS+Crop Sciences, CS+Linguistics, and CS+Music. Two more majors are starting next fall: CS+Economics and CS+Philosophy. A twelfth major in CS+Advertising is in the final stages of approval, and will probably launch in Fall 2020.
[Added January 2022: Since I wrote this answer, we have added two new majors—CS+Animal Sciences and CS+Geography and Geographic Information Science—bringing our total number of CS majors to 14. Otherwise, my answer is unchanged.]
The core curriculum in all nine existing majors is identical—same classes, same instructors, same TAs, same labs, same homework, same programming assignments, same exams, same grading standards, same everything. Nobody will know which species of CS major you are — including the faculty — unless you tell them. (CS+Advertising will have a slightly different core, with one architecture+systems course replacing two separate courses, but with another data-oriented course added in. Some other CS+X’s may adopt that revision.)
Students in all nine majors have access to almost* all the same resources—same faculty, same labs, same computer accounts, same department advisors, same career fairs, same career services. Recruiters and graduate admissions committees cannot tell which species of CS major you are unless you tell them, and they really don’t care even if you do tell them. (Employers and admissions committees don’t really care about your major anyway; they care about you actual accomplishments, your expertise, and your passions.)
The differences are entirely in the upper-division electives. Engineering CS majors take more traditional CS courses. Math&CS students take more math. Stat&CS majors take more statistics (or as the cool kids call it these days, “data science”). CS+linguistics students take more linguistics. CS+CS students take more crop science. CS+Music students take more music.
That’s it. That’s the difference.
