Frequency is a fundamental physical concept defined as the number of cycles or oscillations of a wave or repetitive event that occurs per unit of time. Mathematically, it is the reciprocal of the period, which is the time required for one complete cycle. In physics, frequency is commonly measured in Hertz (Hz), where one Hertz represents one cycle per second. It is critical in the analysis of periodic phenomena, ranging from sound waves and electromagnetic radiation to mechanical oscillations. In biological contexts, frequency measurements may apply to rates of biological processes, such as heart rate or the oscillatory patterns of biochemical reactions, allowing for quantitative description of temporal repetition across various scientific disciplines.