Managing identity
Identity is probably the single most important concept in data management, even if, at its core, it is extremely simple: being able to identify to what instance of an entity some data refers.
The problems with identity arise from the fact that we humans are very flexible in using the available information and we can easily put information in the right bucket, even if it is presented to us in the wrong way.
We are not good at being consistent in the real world but that is not a problem for us as we are very flexible in our data processing. We can easily recognize that two names are referring to the same person, even if they are in uppercase or lowercase, or that it is still the same person with or without the middle name initial, even if we invert the name and surname.
Machines are fast, but not as good at coping with the variability of information as we are, so indicating how to identify instances of an entity, whether they are people, products, documents...
