Preliminary SAT (PSAT)
www.collegeboard.com/student/testing/psat/about.html
Who takes it: all college-bound Sophomores and Juniors
Why: to prepare for the SAT, Juniors can qualify for the National Merit Scholar Program

SAT & SAT Subject Tests
www.collegeboard.com
Who takes it: students applying to four-year universities
Note: SAT Subject Tests are only required for some private schools and recommended for some majors at UCs.
Why: required for admission to any four-year university (the ACT may be used en lieu of the SAT)
When: anytime before November of your Senior year and as many times as you'd like (only your top scores get used)
How to pass: there is no "passing score"  but scores are used to compare applicants for admission and are also combined with GPA to determine eligibility for the CSU eligibility index and the UC scholarship requirement.

ACT
www.actstudent.org
Who takes it: students applying to four-year universities
Why: requireed for admission to any four-year university (the SAT may be used en lieu of the ACT)
When: anytime before November of your Senior year and as many times as you'd like (only your top scores get used)
How to pass: There is no "passing score" but scores are used to compare applicatns for admission and are also combined with GPA to determine eligibility for CSU eligibiity index and the UC scholarship requirement.