SOFTDEVICE_PRESENT is defined in all project that use a SoftDevice. That is used in SDK code that should use different implementation depending on if used with a SoftDevice or not. So in your screenshot, you can see that if the SoftDevice is used (define is present and SoftDevice handler is enabled), the device waits (enters system ON low power mode) by calling sd_app_evt_wait(). If not, it enters system on low power mode by calling __WFE().
SOFTDEVICE_PRESENT is defined in all project that use a SoftDevice. That is used in SDK code that should use different implementation depending on if used with a SoftDevice or not. So in your screenshot, you can see that if the SoftDevice is used (define is present and SoftDevice handler is enabled), the device waits (enters system ON low power mode) by calling sd_app_evt_wait(). If not, it enters system on low power mode by calling __WFE().
