You can also easily explain to students how a piece of complex software works, at the same level of detail. The point is biology is vastly more complex than any software humans have ever written. Evolution selects for spaghetti code.
Redundancy can be achieved through multiple independent systems, e.g. repeating the encoded text in multiple locations; such an approach is not holographic, though. Parity is a more holographic encoding scheme in that redundancy comes from the interaction of multiple pieces of encoded text.
The term is even more applicable when talking about convolutional neural networks in which every neural node significantly contributes to every encoding. Here the similarity to optical holograms becomes quite apparent.
Also, evolution selects for robust code.