The @babel/plugin-transform-for-of Babel plugin transforms ES2015 for...of loops into ES5-compatible code. It enables developers to use modern JavaScript syntax while ensuring compatibility with older browsers and environments. By converting the for...of loop, which iterates over iterable objects (like arrays, strings, and iterators), into a more verbose but widely supported equivalent, this plugin helps maintain broad compatibility without sacrificing developer productivity. This transformation increases code size marginally but offers significant gains in backward compatibility.