What is up with Linux's Apache's ".d"?
Linux and Apache suffix a bunch of files and folders with `d` or `.d`. 

    init.d
    rc.d
    /etc/httpd/conf.d
    /etc/httpd/vhost.d
    
What is the meaning of this convention?
What is up with Linux's Apache's ".d"?
===

Linux and Apache suffix a bunch of files and folders with `d` or `.d`. 

    init.d
    rc.d
    /etc/httpd/conf.d
    /etc/httpd/vhost.d
    
What is the meaning of this convention?