Retiring something you no longer use.
BEFORE REMOVING IT
Export anything you may need: content, user data, records
Take a full backup and store it off the server Check nothing else depends on it
REDIRECTING
If it had public URLs that people visit or that rank in search, redirect them to something relevant rather than leaving 404s.
If the content moved elsewhere, redirect to the new location.
REMOVING IT PROPERLY
Delete the application directory Delete its database and database user Remove its cron jobs Remove any subdomain created for it
Check for files it wrote elsewhere: uploads, cache, logs
WHAT PEOPLE LEAVE BEHIND
Databases counting against plan limits Cron jobs still running and failing Subdomains resolving to nothing Backup archives consuming disk
CHECKING
cPanel > MySQL Databases, Cron Jobs, Domains, and File Manager. You will find things you had forgotten.
WHY IT MATTERS
An abandoned application is unpatched software on your account. Removing it properly closes a route in and frees resources.