You can test this out by transforming your image. Hold Cmd + T, shrink your image, and click enter. Now hold Cmd + T again and bring it back to a larger Size. Sadly, the image will start to be completely blurred and pixelated. By converting it to a Smart Object instead, you have more flexibility in editing because you won’t lose any of the image during transformations.
Once your layer has been turned into a smart object, you can work with Smart Filters. All this means is that any Filter or effect you apply to a smart object will automatically become a ‘Smart Filter.’ You will see it stacked under the layer, and are able to go into it and edit it. You can also turn the effect on and off, and even change the blending mode!
Linked objects can be extremely helpful for when you need to reference and update multiple documents at once. If a change is made on the original document, it will be applied to all of the linked documents when saved.
All you have to do is go to File – Place Linked. Choose the file you’d like to use, and hit place. Now, your original image’s changes will appear on all of the linked files. Hooray!