A "description" of something does not necessarily have to completely describe the thing. For example, one could describe a mouse as "small and grey", but this leaves out a lot of information. Someone who did not know what a mouse was would have a very incomplete picture.
Is there a word for a description which aims to capture something as completely as possible, by reducing it to its components?
I have a feeling there is a word for this which maybe ends in -onomy or -ology.
I don't think it's taxonomy because that refers to an overarching system of description/classification covering many different "things".