Renaissance, meaning rebirth, was a 19th-century term applied by the German art historian Jakob Burckhardt to the culture of Italy from the 14th to 16th centuries - the equivalent of Vasari's 'rinascita' (rebirth). There is much disagreement about its precise definition.
Generally speaking, the High Renaissance covers the later part of this period; in painting it is applied to the early decades of the 16th century, and in particular to the period which witnessed the ascendancy of Leonardo, Michelangelo, Raphael and Titian.