This document introduces key concepts in calculus including limits, derivatives, and rates of change. It discusses:
1) How limits describe the behavior of functions as inputs get closer to a target value. Limits are used to define continuity, derivatives, and tangent lines.
2) How derivatives measure the instantaneous rate of change of a function and are defined as the limit of the average rate of change over infinitesimally small intervals.
3) Properties of continuous functions including that polynomials, rational functions, and basic operations preserve continuity. The intermediate value theorem and existence of zeros are introduced.