root folder

Переводы
корневая папка
корневой каталог
корневая директория
Определения
The top-level folder in a file-system hierarchy, from which other folders and files descend.
The folder that serves as the starting point of a particular directory tree, such as a drive, project, or website.
Слова
root

прилагательное
корневой
folder

существительное
папка