What are Cocoa and Cocoa Touch and how are they relevant to Swift?
Cocoa and Cocoa Touch are frameworks that run on OS X and iOS respectively. Both are primarily implemented with Objective-C and integrated with Xcode (you should also be able to explain Xcode if you get a question on that). They consist of libraries, APIs, and runtimes. Because Swift is an iOS language, it also works with Cocoa and Cocoa Touch. Read the Apple Developer page on Cocoa for more info.
Getting Your Opinion on Swift