MKVToolNix is a powerful, open-source software suite for working with Matroska (MKV) files. One of its key components is mkvmerge , a command-line tool for merging multiple files into a single MKV file. In this article, we'll explore how to use mkvmerge and other tools in the MKVToolNix package to create and manage MKV files. MKV (Matroska) is an open-standard, flexible file format that can contain multiple audio, video, and subtitle tracks. It's widely used for storing and playing back high-definition video content. Using mkvmerge mkvmerge is a powerful tool for combining multiple files into a single MKV file. Here's a basic example of how to use it: