Separating systems.
COMMON USES
shop.yourdomain.com for a separate shop platform support.yourdomain.com for a helpdesk learn.yourdomain.com for a course platform app.yourdomain.com for a custom application
WHY SEPARATE THEM
Different applications conflict when sharing a domain.
Rewrite rules, cookies and session handling collide.
WHAT TO CONSIDER
Each needs its own certificate Each may need its own PHP version Each consumes account resources
FOR SEARCH
Content on a subdomain is treated more separately than a subdirectory.
For a shop or an application that rarely matters.
For content you want ranking with your main site, use a subdirectory.
FOR COOKIES AND LOGIN
Sharing login between a main domain and a subdomain requires deliberate configuration.
Not automatic.
WHAT TO DOCUMENT
Which subdomain runs what, with which database.
With several, you will not remember.
