datum
datum
Noun
pl: data
This term is the singular form of data. While data is frequently used as an uncountable mass noun in common speech, datum is strictly used in technical, scientific, or legal contexts to refer to one individual piece of information.
In geodesy and surveying, the word refers to a reference frame. It serves as the zero-point or baseline from which all other coordinates are calculated, making it a foundational constant rather than a variable.