Apple has unveiled new photo apps in OS X 10.10.3, creating a separate gallery is one of the best ways to manage pictures in photo applications. Putting photos of different scenes in different galleries helps with day-to-day management, such as work and privacy.
The photo app provides us with a simple way to create a new gallery, and it's very easy to switch between those galleries.
The following steps are specific:
1. Close the photo application first (if it is already open)
2. Press and hold the Mac Option key, and click on the photos application on the dock bar
3. Click "New"
4. Give the new gallery a name and select the location where the gallery is stored
5. After selecting a good position, click "Good".
6. To switch between galleries, open the Picture folder and double-click the gallery you want to use. You can also hold down the option key on the MAC and click on the dock bar's photo app, and then select it in the listed gallery.
It is not possible to open two or more galleries at the same time, if one of your galleries is open and then another opens, the first gallery will close before the second opens.