Tareeqa, is the term for an order such as Chishti, Naqshbandi, Mevlev etc; All tareeqas go a long way back and have Silsila, a chain, link or lineage of shaikhs. Shaikh(Leader) guides the group. Membership in an order is not exclusive and one can belong to more than one. There is no competition between Tareeqas. Murshid (spiritual guide) is the leader of a Tareeqa. The followers are called Mureed meaning desirous (desiring knowledge) also called Fakir(needy) or darvesh. A Murshid of a tareeqa appoints a Khalifa who takes over after his death. Zikr, remembrance of Allah. Tasawwuf is to bring Rooh, Soul in a state of purification. Ishq e Allah (love of God)..
(Here is part of a anonymous Persian poem called What isTasawwuf* translated by Dr Allan Godlas of U.GA).
What is Tasawwuf? Good character and awareness of God.
That’s all Tasawwuf is. And nothing more.
What is Tasawwuf? Love and affection.
It is the cure for hatred and vengeance. And nothing more.
What is Tasawwuf? The heart attaining tranquility–
which is the root of religion. And nothing more.
*Dr alan Godlas has a very comprehensive website at www.uga.edu/sufism .