All Creative Commons licenses are composed of three layers:
- The legal code (example) -- making the license enforceable in law
- The common deed (example) -- this is the human-readable license
- Machine readable code – this enables searching and filtering by CC license type
To see how the three layers work, explore this interactive graphic from Creative Commons.

[3 Layers Image (c) 2011, Creative Commons, Nathan Yergler, Alex Roberts. Licensed under CC BY 3.0 Unported]