The structure of your thesis will depend on the kind of thesis you are writing.
In some cases there are conventional structures that are expected in the discipline. For example, theses that are empirical, experimental, and/or quantitative in nature generally follow the structure: introduction including aims, literature review, methodology, results, discussion, conclusion.
In other theses that are not quantitative in nature (typically those dealing with ideas, concepts, theories and arguments), the structure will arise from the nature of the subject matter and your treatment of it. In these theses, the structure varies greatly. It may be based on considerations such as your research design or methodology, or your individual stance on the topic.
For example, if you’re a researcher in the humanities, you have to make many decisions about the scope and focus of your thesis topic, and how best to present these to your reader. You need to pay special attention to communicating the structure so that your readers feel comfortable. They should always know which direction you’re going in and why.
Since your thesis needs to show your own analysis of the literature and other evidence/data you might be using, you need to have a clear analytical framework (or set of analytical frameworks) to make this analysis clear to the reader. You may need to experiment with this framework, in outline form, several times before committing yourself to writing.