Definition: SumatraPDF is a free, open-source, lightweight PDF reader for Windows. It supports a variety of document formats including PDF, ePub, MOBI, CHM, XPS, DjVu, CBZ, and CBR.

Function: Provides a simple and efficient interface for viewing and reading PDF and other document formats without the bloat of more feature-heavy alternatives.

Components:

 * '''User Interface''': Minimalist design focused on ease of use and performance.
 * '''Document Viewing''': Supports multiple document formats, offering fast rendering and smooth scrolling.
 * '''Customization''': Allows for customization through settings and command-line options.

Features:

 * '''Lightweight and Fast''': Small installation size and quick performance.
 * '''Multi-Format Support''': Opens PDF, ePub, MOBI, CHM, XPS, DjVu, CBZ, and CBR files.
 * '''Portable Version''': Available as a portable application, which can be run from a USB drive without installation.
 * '''Keyboard Shortcuts''': Extensive support for keyboard shortcuts to enhance usability.
 * '''Continuous Updates''': Regularly updated with new features and bug fixes.

Usage: Ideal for users seeking a fast, lightweight, and versatile document viewer without unnecessary features.

Downloading and installing SumatraPDF:

 * Visit the official website: [SumatraPDF](https://www.sumatrapdfreader.org/)
 * Download the installer and follow the instructions to install.

Opening a PDF file:

 ```bash
 sumatrapdf.exe filename.pdf
 ```
 This command opens the specified PDF file using SumatraPDF.

Customizing settings:

 * Access settings through the `Settings` menu to adjust preferences such as default zoom level, interface language, and rendering options.

Using keyboard shortcuts:

 * Common shortcuts include:
   * `Ctrl + O`: Open a file
   * `Ctrl + P`: Print the document
   * `F11`: Toggle fullscreen mode
   * `Ctrl + L`: Rotate the page
   * `Ctrl + Shift + +`: Zoom in

SumatraPDF: A free, open-source, lightweight PDF reader for Windows that supports multiple document formats. Known for its speed, simplicity, and efficiency, SumatraPDF is a popular choice for users looking for a fast and versatile document viewer.