Sufism is the inner way of Islam. Though it exists within the framework of Islam, its focus is not the rules of orthodox practitioners, but the direct experience of the individual and his or her ascendancy through various spiritual states and stages to the ultimate goal of unity with Divine energy or spiritual Reality.
This emphasis has in the past, and still does, put Sufism in conflict with certain orthodox Muslims. In particular, the use by some Sufi orders of music, poetry and movement has been criticised by externalist elements.
However, these mystical practices have been validated by recognised figures of authority within Islam, including the Prophet Muhammad, and also received widespread support within more tolerant Islamic communities.
From a Sufi perspective, Islam is merely the husk, whilst Sufism is the kernel that gives it life.