What `sudo` changes
On Unix-like systems such as Linux and macOS, ordinary programs run under your user account, which limits what files and settings they can change. `sudo`—short for “superuser do”—asks a system authorization tool to start a particular command with the identity and permissions of another account, usually the all-powerful administrator account called `root`.
That change matters because the operating system checks permissions when a program tries to read or alter protected resources. A command that cannot edit a system-owned file as an ordinary user may be allowed to do so when launched through `sudo`.
A narrow request, not a magic override
The system checks whether your account is authorized to make the request. Depending on its configuration, it may ask for your password; it may also remember that authentication briefly, so repeated commands do not always prompt again. Administrators can restrict which users may run which commands.
Crucially, `sudo` does not turn off the operating system’s protections. It grants the launched command extra authority, while other rules—such as file-system restrictions or security controls—can still apply. The command’s own behavior also matters: a mistake made with administrator privileges can alter or delete files that your account could not normally touch.
Why the distinction matters
Using `sudo` only for the command that needs elevated access keeps routine work running with ordinary permissions. For example, installing system software may require administrator authority, while editing a document in your home folder generally does not. The practical safeguard is to treat each `sudo` command as permission for that program to make consequential changes, not as a harmless prefix that makes an instruction safer or more correct.
