You download an installer, a firmware image, or a database dump. Next to the download link the site lists something like: SHA-256: 3a7bd3e2360a3d29eea436fcfb7e44c735d117c42d1c1835420b6b9942dd4f1b Most people ignore it. Here's why you shouldn't, and the fastest way to check it on every OS.
Source: [Dev.to](https://dev.to/yuus_company/how-to-verify-a-file-checksum-on-macos-linux-and-windows-and-why-you-should-4mnm)