There is only one Islam. However there are Madhabs. we are all encourged to follow one madhab which will nearly always be the one in our area. We are also encourged to learn about each of the madhabs and follow the one that is best for us.
Now for sects, if you mean sects as defined in Christianity, there are none. If a person follows the Pillars of Faith and the Foundations of Islam they are Muslim, even if we disagree with the way they follow Islam.
However there are groups that call themselves Muslim, but they do not follow the Pillars of Faith or the Foundations of Islam. We do do not see them as sects, they are non-Muslim not matter what they call themselves.
However there will one day be division in Islam and it may have already begun. However, no matter how much Islam divides only those who follow the sunnah will be Muslim.