Why is Photo on MacBook Pro automatically importing my photos from iPhone? I'm not plugging in the USB cable from iPhone to the MacBook. Every time I add new photos on my iPhone, they automatically import to Photos to the MacBook. If I delete them from my MacBook, they also are deleted from my iPhone. 

How do I undo this?
You have turned on iCloud sync of your Photos on both your MacBook and your iPhone. To stop this from happening, you need to turn this off.

On the MacBook, System Preferences > iCloud. Uncheck the box:



On the iPhone, Settings > iCloud: