Just like you need a a BitTorrent client in order for your computer to understand and use BitTorrent and magnet links. There are dozens of them out there for every operating system, but Wikipedia has a good list  of all the major clients available. Every client has a different set of features, and picking one is a matter of personal preference. We recommend using qBittorrent  . It’s free, fast, feature-rich, opensource, and works on every operating system.