Overview
The basic A-Level course consists of six modules, four standard (C1, C2, C3, and C4) and two modules that can be chosen by the student or school/college, etc. The C1 through C4 modules are referred to by A-level textbooks as "Core" modules, encompassing the major topics of mathematics such as logarithms, differentiation/integration and geometric/arithmetic progressions, to name but a few.
The two chosen modules for the final two parts of the A-Level are determined either by a student's personal choices or the course choice of their school/college, but commonly take the form of S1 (Statistics) and M1 (Mechanics)
Read more about this topic: Advanced Level Mathematics