In statistics, identifiability is a property which a model must satisfy for precise inference to be possible. A model is identifiable if it is theoretically possible to learn the true values of this model's underlying parameters after obtaining an infinite number of observations from it.

What does detectable mean?

If you can or ought to be able to notice something, it's detectable. An odor in your fridge is detectable. Or, there can be a detectable coolness in someone's behavior toward you. Detectable is related to the word detective, one of the guys on the police force who finds clues and tracks down bad guys.

What do you mean by entity?

1a : being, existence especially : independent, separate, or self-contained existence. b : the existence of a thing as contrasted with its attributes. 2 : something that has separate and distinct existence and objective or conceptual reality.