How to implement a copyTo feature and what is the difference b/w copyTo and shareWith

I am familiar with the share functionality on IOS. I share items in my app using

[[UIActivityViewController alloc] initWithActivityItems:items applicationActivities:nil];

This only shows a few app but certain apps like Imgur are missing.However I noticed that in Google Drive there is another option that says CopyTo and it looks like this

How do i add the copyTo feature ? Whats the difference between sharing and CopyTo ?

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