In short I can tell you the difference between the two services as follows:
1. The services which are set to Automatic will start during the boot process itself.
2. The services which are set to start as Delayed will start shortly after the boot.
So “shortly after boot" it means 2 minutes after your last "automatic" service has started, by default. This can be achieved by configuring with the use of registry key.
The registry keys are as below :
· HKLM\SYSTEM\CurrentControlSet\services\<service name>\DelayedAutostart:-It will have the value as 1 if delayed and as 0 if not delayed.
· HKLM\SYSTEM\CurrentControlSet\services\AutoStartDelay or HKLM\SYSTEM\CurrentControlSet\Control\AutoStartDelay (for Win 10): Here the decimal number of seconds to wait are needed to create this one and it applies globally to all Delayed services.