What does unchecking the "Import sequences natively" option do exactly?

[김구정]

I am just curious and would like to know what exactly does unchecking the "Import sequences natively" option do in comparison to having it checked.

[Peru Bob]

If you are rendering a sequence with native sequence support, the GPU setting in Adobe Media Encoder is used and the project setting is ignored. In this case, all GPU rendering capabilities of Premiere Pro are utilized directly in Adobe Media Encoder.

from here:

Media Encoder Help | New features summary

[PolkaFever]

Thanks @Peru Bob 
I make sense. 🙂

[eckiAMETeam · Accepted solution]

See https://helpx.adobe.com/media-encoder/using/preferences.html:

Import Premiere Pro sequences natively:

Allows Premiere sequences to be imported on systems where Premiere Pro is not installed.