Introduction to LaTeX

LaTeX is a typesetting system based on TeX, widely used to produce high-quality scientific and mathematical documents. It was developed by American computer scientist Leslie Lamport in the 1980s.

TeX is a low-level typesetting engine developed by Donald Knuth, mainly used for handling complex mathematical formulas and high-quality typesetting.

LaTeX provides a higher-level abstraction on top of TeX, allowing users to focus more on content without worrying too much about typesetting details.

Unlike common word processing software (such as Microsoft Word), LaTeX uses plain text files to describe the structure and content of a document, and generates the final PDF file through compilation. LaTeX is particularly suitable for handling complex mathematical formulas, references, cross-references, etc.

LaTeX was originally designed to facilitate the typesetting of academic papers and technical documents, especially in fields such as mathematics, physics, and computer science. Over time, LaTeX has gradually become one of the standard tools in academia and publishing.

LaTeX Features

• High-quality typesetting: LaTeX is known for its professional typesetting effects, especially excellent handling of mathematical formulas. It can automatically adjust document formatting and produce high-quality typesetting that meets publishing standards.
• Markup language based: LaTeX uses a plain-text markup language format. Users define the structure and format of a document by entering specific commands and tags. For example, users use \section{} to define sections, and \textbf{} to bold text.
• Cross-platform support: LaTeX is cross-platform and supports operating systems such as Windows, macOS, and Linux. Output documents are usually in PDF format and display consistently across different platforms.
• Suitable for academic writing: LaTeX is very suitable for writing academic papers, books, technical documents, reports, etc., especially documents containing a large number of mathematical formulas, references, and complex typesetting requirements. It has excellent support for bibliography management, formula input, and typesetting.
• Automated document management: LaTeX provides powerful automation features in long documents, books, or papers, such as automatic numbering, automatic table of contents generation, cross-references, automatic formula typesetting, etc. It can automatically handle citations, reference lists, etc., making it ideal for documents requiring precise formatting.
• Open source and free: LaTeX is open source, and anyone can download and use it for free. Meanwhile, the LaTeX community is very active, providing a large number of templates, packages, and tips to help users improve typesetting efficiency.

How does LaTeX work?

• LaTeX is not like traditional WYSIWYG (What You See Is What You Get) editors. You do not directly see the final typeset result. Instead, you edit a plain text file and input the document's content, structure, and formatting instructions. This file usually has the extension .tex.
• Writing LaTeX source code: First, you use a text editor (such as TeXworks or TeXstudio) to write the LaTeX source file. You specify the document structure, title, paragraphs, formulas, tables, etc., in the file, and use LaTeX commands to specify how to format them.
• Compilation: Then, you compile the .tex file into PDF or other output formats using a LaTeX compiler (such as pdflatex). During compilation, LaTeX automatically generates the table of contents, tables, formula numbering, references, etc.
• Generating the final document: The compiled output is the final document. You can view the PDF version of the result, which will generate high-quality typesetting according to your formatting requirements.

Why use LaTeX?

• Academic writing: If you are a researcher, scholar, or student, LaTeX is ideal for writing academic papers, reports, books, etc., especially documents that require complex mathematical formulas and references.
• High-quality typesetting: LaTeX automatically handles typesetting details and can generate document formats that meet international publication standards. Whether it is fonts, line spacing, margins, or the format of section headings, LaTeX can precisely control them.
• Complex document structure: LaTeX is suitable for handling large documents (such as books, theses, technical manuals). It can automatically generate tables of contents, indexes, and references, and supports cross-references and automatic numbering.
• Mathematical and scientific documents: LaTeX is the preferred tool in fields such as mathematics, physics, and engineering because it can conveniently input and typeset complex mathematical formulas.

Comparison between LaTeX and Word

The LaTeX workflow can be summarized in three steps: write source code, run compilation, and get the PDF.

The .tex file we write is just an ordinary plain text file that can be opened with any editor. The compiler is responsible for turning it into the final PDF output.

Basic Workflow of LaTeX

The basic process of writing a document with LaTeX is as follows:

• Write the source code: Use a plain text editor to write the .tex file, which contains the document structure, text, and commands.
• Compile the document: Use a LaTeX compiler (such as pdflatex, xelatex) to convert the .tex file to PDF or other formats.
• View the result: The generated PDF file can be viewed directly, and the content will be automatically typeset according to the source code.

For example, a simple LaTeX document is as follows:

The Core Idea of LaTeX

The core idea of LaTeX is the separation of content and formatting:

• Users only need to focus on the content and structure of the document, and LaTeX will automatically handle the typesetting details.
• Use commands and environments (such as \section, \begin{itemize}) to define the structure and style of the document.
• Formatting adjustments can be made by modifying the document class or loading packages, without directly modifying the content.

Relationship between TeX, LaTeX, Packages, and Distributions

These are the concepts that beginners most often confuse. Once you understand them clearly, you won't get lost when choosing tools or installing environments later.

The entire TeX ecosystem can be divided into four layers, from bottom to top: engine, format, packages, and editors.

The engine is the program that actually does the typesetting work. Common ones include TeX, pdfTeX, XeTeX, and LuaTeX. Among these, XeTeX and LuaTeX natively support Unicode and system fonts, which is why they are recommended for compiling Chinese documents.

A format is a set of command rules built on top of an engine. LaTeX is currently the most popular format.

Packages are plugins that further extend functionality on top of a format, such as Chinese support (ctex), mathematical formula enhancement (amsmath), and page layout (geometry). CTAN hosts more than five thousand packages.

Finally, a collection that bundles the engine, format, and a large number of macro packages together for one-time installation is called a distribution, such as TeX Live and MiKTeX.

An editor is not a compiler. Overleaf, TeXstudio, and VS Code are only responsible for writing code and triggering compilation; the actual typesetting is done by the engine in the distribution. So in a local environment, installing only an editor without a distribution will not compile PDFs (Overleaf is an exception; its cloud comes with a full distribution).

Advantages and Use Cases of LaTeX

LaTeX is not a universal tool, but in the following scenarios, its advantages in efficiency and quality are very obvious.

Conversely, there is no need to force LaTeX in these situations: posters requiring heavy graphic design, office documents that need multi-person real-time annotation and circulation, and short documents with few formulas that must be produced the same day; Word or specialized tools are more convenient.

LaTeX's learning curve is steep at first and then flattens out: in the first few days you may feel like 'even changing the font size requires looking up commands,' but if you persist through the basics of this series, you will appreciate the long-term benefits of automated typesetting.

Comparison of Common Distributions

A distribution solves only one problem: it saves you from installing engines and macro packages one by one.

When downloading TeX Live or macro packages from a domestic network environment, it is recommended to switch the software source to domestic mirrors such as Tsinghua University TUNA; the speed can be an order of magnitude faster.

Editor Selection

The editor determines your 'writing' experience; it can be changed at any time and is independent of the distribution.

It is recommended to start with Overleaf firsthttps://www.overleaf.com/, with zero configuration you can directly follow the tutorial and type code; when you need offline writing or version control later, set up a local environment.

Sneak Peek: A Complete LaTeX Source Code

Before formally setting up the environment, let's take a look at what a real LaTeX document looks like.

The following source code is complete and compilable, containing Chinese text, a title, and two mathematical formulas.

After compiling this source code, the resulting PDF page is as follows:

It is completely normal not to understand these commands now; every subsequent article in this series will explain them one by one.

Here you only need to remember two structures: the part from \documentclass to \begin{document} is calledpreamble, used for global settings; the part between \begin{document} and \end{document} is calledbody area, which is where you write the content.