perioadele

Perioadele are the plural form of the Romanian word perioadă and refer to defined spans of time that are distinguished by particular events, processes, or conditions. The term, derived from Latin perioda, is used across disciplines to denote meaningful divisions of time.

In historiography, perioadele are used to segment the past into named phases, such as antichitatea, Evul Mediu, perioada modernă and perioada contemporană. In geology, periods are formal subdivisions of eras in the geologic timescale, typically shorter than eras and longer than epochs; well-known examples include Cambrian, Jurassic and Cretaceous. In astronomy and physics, the concept of period describes the duration of repeating phenomena, such as orbital periods or oscillation periods. In mathematics, the period of a function is the length of one complete cycle of its repetition.

Perioadele may overlap with or be defined alongside other time divisions such as eras, epochs or ages, and their exact boundaries vary by field and convention. The term is often used to indicate a phase with characteristic features rather than a strict calendar date, allowing scholars to organize observations, data, and narratives around notable shifts in culture, nature, or behavior.