The SAT (technically known as the SAT I) is a general test of verbal and quantitative reasoning accepted for U. S. college admissions. The test is required for admission to undergraduate programs of most US universities. Many universities also require you to take SAT-II tests.
SAT-I : Reasoning Test
The SAT tests the skills you’re learning in school: reading, writing and math. Your strength in these subjects is important for success in college and throughout your life.
The reading section includes reading passages and sentence completions.
The writing section includes a short essay and multiple-choice questions on identifying errors and improving grammar and usage.
The math section includes questions on arithmetic operations, algebra, geometry, statistics and probability.
SAT-II : Subject Tests
The SAT-II subject tests are one hour, primarily multiple-choice tests that measure your knowledge of particular subjects and your ability to apply that knowledge. Many universities may require you to take this along with SAT-I.
The SAT is developed and administered by the US-based "College Board". This implies that Collegeboard sets the questions, conducts the test, and sends each examinee the score report.
For detailed information about SAT tests, go to College Board .