These terms originally applied to the quantitative meter of classical poetry. The word 'pentameter' indicates that a line has five of these feet. The word ' iambic' describes the type of foot that is used (in English, an unstressed syllable followed by a stressed syllable). That rhythm is measured in small groups of syllables these small groups of syllables are called ' feet'. The term describes the particular rhythm that the words establish in that line. Iambic pentameter is a commonly used metrical line in traditional verse and verse drama.
