What are LaTeX Commands?

In LaTeX, documents are crafted using commands to control formatting and structure, providing users with precise control over the appearance of their content. Whether you’re a beginner or an experienced user, mastering LaTeX commands opens the door to creating professional and beautiful typeset documents.

What is a Command in LaTeX?

In LaTeX, a command is a directive instructing the typesetting system to perform a specific action or format text in a particular way. A command is initiated with a backslash (\), followed by either uppercase or lowercase letters, typically chosen descriptively. They control the formatting, structure, and layout of a document.

LaTeX: Command Structure

The command structure varies and can be exemplified as follows:

• Basic command: \command
• Command with a mandatory argument: \command{argument}
• Command with an optional argument: \command[optional argument]{argument}

Commands often incorporate parameters, which are options influencing the command’s functionality. These parameters, known as arguments, are enclosed in either curly braces ({}) or square brackets ([]).

Multiple arguments, enclosed in curly braces or square brackets, may be required. Mandatory arguments (in curly braces) must be provided, while optional arguments (in square brackets) are not obligatory. If no optional argument is specified, the command defaults to a predefined value.

For instance, consider the \documentclass command:

• \documentclass{article} sets the base font size to 10 points, the default for the ‘article’ class.
• \documentclass[a4paper,11pt]{article} customizes the document for A4 paper with a base font size of 11 points, overriding the default values.

Note: Commands in LaTeX are case-sensitive, so \section and \Section would be treated as different commands. Additionally, commands may take parameters, values, or information that modify the command’s behavior.

Types of Commands

LaTeX commands can be classified into two main types:

1. Type I

These are commands that start with a backslash (\) and are followed by letters. They may consist of a single command or a combination of commands. For example:

• \section: This command denotes the beginning of a new section in a document. It automatically formats the section heading, numbering, and spacing according to the document’s style.
• \textbf{}: This control sequence is employed to apply bold formatting to the enclosed text. The text within the curly braces will appear in boldface when the document is typeset.

Usage:

• To start a new section: \section{Introduction}
• To make text bold: \textbf{Important information}

2. Type II

Some commands consist of a backslash (\) followed by a single special character. These are often used for specific formatting purposes. For example:

• \( \): These commands are used for inline mathematical expressions. They allow you to include mathematical equations within the text flow, enclosed by the specified delimiters.
• \\: This command is used for line breaks. It signifies the end of a line and the beginning of a new one, facilitating proper formatting and layout.

Understanding the syntax and usage of LaTeX commands, including their optional and mandatory parameters, is crucial for effective document formatting.