A thesis tells an audience what to expect from the rest of what they are reading. The thesis directly answers the question being asked of you; It is putting the question/subject into a different way rather than the subject itself.
Arrangement
Is usually a sentence at the beginning of your paper (most often at the end of the introduction) that presents the argument to the reader. The rest of the paper is set by your thesis, which uses evidence that persuades the reader.
Creation
A thesis takes a long process of thinking. Before you develop your argument for any topic, you must collect evidence, look for the relationships between facts; think about how those relationships work and how they relate. After doing this you should have a thesis that presents a main idea for your topic/argument that can be supported with evidence.