The SAT is comprised of two sections: Evidenced-Based Reading & Writing and Math, each worth 800 ppoints. A student's SAT score is the sum of these two sections, with a score of 1600 being the higest.
In addition, SAT offers an optional writing assessment (essay) which a few colleges require.
A few selective colleges require SAT II Subject Tests. These tests are given on the same day as the regular SAT, except for the March date. You may take the SAT or up to three SAT II Subject Testsduring a given test administration. Check the SAT website to see what subject tests are available on a given test date. The fees for SAT II Subject Tests vary. Again, check the website for details.