What is the beta of a bipolar junction transistor?

In a bipolar junction transistor (BJT), beta (often symbolized by the Greek letter beta or h_FE) represents the transistor's forward DC current gain in a common-emitter configuration. It is defined mathematically as the ratio of the collector current to the base current (Ic / Ib). Because a very small change in base current can control a much larger change in collector current, the beta value describes exactly how much the input signal is amplified. For example, a beta of 100 means that 1 milliamp of base current will permit 100 milliamps of collector current to flow. Distractors involving frequency or switching speed relate to other transistor specifications, such as the transition frequency (f_T) or switching time, not the current gain.