TestOut Linux Pro Practice Test 2025 – Complete Exam Prep Guide

The 'du' command, which stands for "disk usage," is primarily used in Linux and Unix-like operating systems to estimate and report the file space usage of directories and their contents. When you run this command, it provides information about how much disk space a directory occupies. This is helpful for understanding and managing disk usage on a system, especially when trying to identify which directories consume the most space.

The size reported by 'du' can be specified in various formats, such as kilobytes, megabytes, or blocks, based on the options used. Therefore, you can rely on this command to effectively assess the overall size of a directory, including all its subdirectories and files.

While the number of files in a directory and the modification dates of files are important information, those are not the primary outputs provided by the 'du' command. Other commands like 'ls' or 'find' can give you details on file counts and modification dates, but the core functionality of 'du' centers around reporting size, making it the definite choice for the question.