We adhere to the Leibnitz based Gregory Chaitin's understanding of comprehension as compression.
"For any finite set of scientific or mathematical facts, there is always a theory that is exactly as complicated, exactly the same in bits, as the facts themselves. (It just directly "outputs them ~as is." without doing any computation.) But that doesn't count, that doesn't enable us to distinguish between what can be comprehended and what cannot, because there is always a theory that is as complicated as what it explains.
A theory, an explanation, is only successful to the extent to which it compresses the number of bits in the facts into a much smaller number of bits of theory."
Compression: "That's how we can tell the difference between real theories and ad hoc theories."
Something you have understood is something you can program yourself.