Despite its importance, there isn't always a great deal of agreement on just what secularism really is. Part of the problem lies in the fact that the concept of "secular" can be used in a couple of ways which, while closely related, are nevertheless different enough to make it difficult to know for sure what people might mean. The word secular means "of this world" in Latin and is the opposite of religious. As a doctrine, secularism is usually used to describe any philosophy which forms its ethics without reference to religious dogmas and which promotes the development of human art and science.

Secularism is a way of conducting state business, definition of which may change from country to country, depending on cultural,economical, geographical, geo-strategical conditions of that country.

While it is true that in general secularism indicates that state laws shall not be based on teachings of any religion or any divine principles...the practices may differ in certain aspects.

In France for example, secularism is based on a written contract (1905) between State and the Church, which is basically an agreement that neither party shall interfere with the realm of the other.

In Turkia there is no such written agreement. The founders of the republic have,
1. Abolished the Caliphate,
2. Started a new state institution called DEPARTMENT OF RELIGIOUS AFFAIRS (not DEPARTMENT OF ISLAMIC AFFAIRS), with sole intention to provide secular state control over the complete religious realm.

Their message was "There will be no religious interference on State affairs, but the State will exercise control on all religious affairs, so that no one religion (or sect.) in the country can gain unfair advantage on any other - based on sheer weight of numbers (population).

Whether or not the intentions of the founders were fully followed afterwards, is a different discussion .