The ACT is a test that is currently used by colleges and universities across the United States to judge students’ college readiness. It is one of many criteria used by admissions officers to decide who will be admitted. It is also a graduation requirement in some states and school districts. The SAT is a similar test that is used in a similar way. Colleges and universities that require an admissions test will accept either the ACT or the SAT so students can choose which one is the better fit for their skills.
Read more on figuring out which test is a better fit for you.