For example, Babel includes required polyfills automatically based on Browserslist definitions when using their @babel/preset-env preset to achieve automatic compatibility with the desired target browser.
The list can be stored e.g. in a dedicated .browserslistrc file, the browserslist key in package.json in the current directory or parent directories, or the BROWSERSLIST environment variable.
To debug a Browserslist query, the browserslist CLI can be used.
npx browserslist "last 2 version, >5%"