Madhyamaka (Sanskrit: मध्यमक, Madhyamaka, Chinese: 中觀派; pinyin: Zhōngguān Pài; also known as Śūnyavāda) refers primarily to a Mahāyāna Buddhist school of philosophy founded by Nāgārjuna. The school of thought and its subsidiaries are called "Madhyamaka"; those who follow it are called "Mādhyamikas". According to Madhyamaka all phenomena are empty of "substance" or "essence" (Sanskrit: svabhāva) because they are dependently co-arisen. Likewise it is because they are dependently co-arisen that they have no intrinsic, independent reality of their own.
Whatever is dependent arising
—Nāgārjuna, Mūlamadhyamakakārikā 24:18
Read more about Madhyamaka: Origins and Development, Schools, Concepts, Understanding in Buddhist Tradition, Understanding in Modern Scholarship