Here is the general layout of your thesis, after the front matter, in the section with Arabic page numbers.
The major divisions are chapters. You may also have
one or more appendices, which are at the same level as
chapters. See Section 7.1, “The \chapter command” and Section 7.3, “The \appendix command”.
You can subdivide chapters and appendices using the
commands described in Section 7.2, “The \section, \subsection, and \subsubsection
commands”.
Last in your thesis comes the literature citations; see
Section 7.4, “The References and Bibliography environments”.