Tantrism and tantric ideas begin with notions in line with all forms of Buddhism, namely, the idea that Ultimate Reality is a singular Unity. It is not the apparent multiplicity of the present world around us (maya). Tantrism, which is a key component of Vajrayana, then goes beyond these notions to their representation in the symbol of the sexual union between male and female (see yab-yum). This union is a symbol of the identity of the multiple nature of this world (maya), which is represented by the male, with the unity and wisdom of cosmos, represented by the female. In some schools, the symbol of intercourse is reenacted as part of meditation.