Core vs Elective language
Core is the standard language course; Elective is the deeper literature course.
English Core (301) is the compulsory-style English most students take: reading, writing and functional grammar with some literature. English Elective (001) is a literature-heavy course with more poetry, drama and long-form writing.
You cannot take the Core and Elective versions of the same language together. Universities treat both as English for eligibility, so pick on interest and workload rather than on admissions.