Nous, sometimes equated to intellect or intelligence, is a term from classical philosophy for the faculty of the human mind necessary for understanding what is true or real. English words such as "understanding" are sometimes used, but three commonly used philosophical terms come directly from classical languages: νοῦς or νόος, intellēctus and intellegentia. To describe the activity of this faculty, the word "intellection" is sometimes used in philosophical contexts, as well as the Greek words noēsis and noeîn. This activity is understood in a similar way to the modern concept of intuition.