Where a domain serves from.
WHAT IT IS
The directory a domain serves files from.
WHY IT MATTERS
Wrong document root means the wrong content, or no content.
WHEN YOU NEED TO CHANGE IT
Installing an application expecting the web root to point at a subdirectory Restructuring your account Fixing a site serving the wrong content
THE FRAMEWORK CASE
Many modern frameworks expect the web root to point at a public directory inside the project.
Serving the project root exposes configuration files, including credentials.
That is a real security problem and a common misconfiguration.
HOW TO CHANGE IT
cPanel, Domains. Each domain shows its document root with an edit option.
AFTER CHANGING IT
Test immediately. A wrong path means the site does not load.
WHAT TO CHECK
That the path exists That it contains what you expect That no sensitive files are now web-accessible