High school diploma
Most common qualification for high school leavers aged around 18
AP
Advanced Placement - a series of externally-assessed subject-based tests held to be equivalent to A level or the IBDP
SAT
Standardised Assessment Tests - a series of assessments taken for university entry in the US. Scored out of 1,600
ACT
American College Testing - an alternative set of standardised tests accepted by US universities. Scored out of 36
NEASC
New England Association of Schools and Colleges - one of several boards accrediting American schools
CIS
Council of International Schools - an accreditation agency for international schools