How to use default iOS images?

I know how to use images in iOS application. But I don't know how to use default images like share or bookmark icons which are mention in developer site.

I want to use them. Do I need to download those set of images or those are available in Xcode?

If we have to download them, where I can get those icons?

What does rendered image mean on Iphone?

Original rendering mode renders an image as they appear in the original source image. This might be what we expected from most images, such as product images and onboarding illustrations. Example of illustration and article images. Not every image is created equals.

What is UIImage?

An object that manages image data in your app.

Now starting from Swift 5.1 and Xcode 11 you can load 1 from over 1500 system images with the new UIImage Api UIImage(systemName: "imageName") which are vector based so no worries about qualities for different sizes

https://developer.apple.com/design/resources/

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