The basis of dry friction is discussed using an independent oscillator model with longitudinal motion. This sample system is treated both numerically and with analytical methods. At vanishing velocity a sliding dry friction force is calculated which is smaller than the pinning force. At finite but not too large velocities the system displays bifurcation, chaotic motion, resonances at fractional and multiple frequencies of the oscillator, and hysteresis. Dry friction results from these complicated features. This force varies rapidly with velocity within this range, however, with a roughly constant mean value.