What is the built-in file manager in modern Windows called?

The built-in file manager in modern Windows is called File Explorer. It lets users browse drives and folders, open files, copy or move items, search locations, and manage storage devices.

File Explorer evolved from Windows Explorer, the name used by earlier Windows releases. Windows 95 introduced Windows Explorer as part of a broader redesign that replaced the older Windows 3.x File Manager and Program Manager workflow. Microsoft changed the name to File Explorer in Windows 8.

The quickest keyboard shortcut is Windows key + E, which opens a new File Explorer window. Its familiar folder interface is separate from the Windows desktop shell, although Explorer components have historically been closely connected to the desktop, taskbar, and file-management functions.

The alternatives in the question belong to other platforms: Finder is Apple’s macOS file manager, Nautilus—now commonly branded GNOME Files—is associated with GNOME Linux desktops, and Dolphin is the default file manager for KDE Plasma.