# TexLive Documents

**Document class** is the first line in every LaTeX file and sets the document type. The three standard classes are `article` (for papers and short documents), `book` (for long documents with chapters), and `report` (for reports and theses). Each class defines default margins, font sizes, section hierarchy, and spacing.

```latex
\documentclass{article}
\title{My Paper}
\author{Author Name}
\date{2026-08-19}
\begin{document}
\maketitle

\section{Introduction}
Content here.

\end{document}
```

`\maketitle` generates a title page with title, author, and date. Omit `\date{...}` to use today's date; use `\date{}` to omit the date entirely.

**Document options** modify class behavior. Pass them in square brackets: `\documentclass[12pt, twoside]{book}`. Common options: `11pt` or `12pt` (font size, default 10pt), `twoside` (left/right margins differ for binding), `twocolumn` (two-column layout), `landscape` (rotate to landscape). `article` defaults to single-sided; `book` defaults to two-sided.

**Book documents** use chapters: `\chapter{Chapter Title}` (level 1), `\section{Section}` (level 2), `\subsection{Subsection}` (level 3). Articles use `\section`, `\subsection`, `\subsubsection` (no chapters). Reports are similar to articles.

**Front matter** in books uses `\frontmatter`, `\mainmatter`, `\backmatter` to set page numbering and numbering reset:

```latex
\documentclass{book}
\begin{document}
\frontmatter  % i, ii, iii, iv (Roman numerals)
\chapter{Preface}

\mainmatter   % 1, 2, 3, ... (Arabic numerals, chapter 1 = page 1)
\chapter{Introduction}

\backmatter   % continues numbering, no chapter numbers
\chapter{Appendix}
\end{document}
```

Without `\frontmatter` and `\mainmatter`, all pages use the same numbering scheme.

**Abstract** in articles: use the `abstract` environment:

```latex
\begin{abstract}
Summary of paper.
\end{abstract}
```

This generates a centered, indented block. Books don't have a standard abstract command; create one manually or use a custom environment.

**Table of contents** is generated automatically from section headings:

```latex
\tableofcontents
```

This must be compiled twice to resolve references (first pass generates `.toc` file, second pass reads it). The TOC appears where you place this command—usually after `\maketitle` but before the first section.

Starred versions like `\section*{Unnumbered}` create sections that don't appear in the TOC and aren't numbered.