Ch1-1 What's AC , DC and small signal

DC is a type of electrical current that flows in one direction only.

AC is an electrical current that periodically reverses its direction, commonly used in power grids and electrical appliances.

A small signal is a relatively weak electrical signal compared to a larger, constant signal. It's often superimposed on a DC bias or a larger AC signal, and its amplitude is typically small enough to allow for linear analysis.

These three terms are fundamental concepts in electronics. Understanding the differences between AC, DC, and small signals is essential for analyzing and designing electrical circuits.