This document provides an overview of key concepts in motion in one dimension including: 1) Frame of reference establishes the axis and defines where zero position is and the positive direction of motion. 2) Position is measured as a number line from the zero point. Displacement is the change in position between two points, regardless of path, while distance considers the actual path traveled. 3) Time intervals are defined similarly to displacement as the difference between two time points. Average velocity is displacement over time interval while instantaneous velocity considers an infinitesimally small time interval.