Geometry Node Doc confusion Field/single value

Hello,

Q1:
Can anyone clarify what is a “single value” and “Single Real Value”?
Probably a definition in the doc is required?
Thanks!
https://docs.blender.org/manual/en/latest/modeling/geometry_nodes/fields.html#field-visualization

Q2:
Also why does a function is called as a field instead calling it a function or method. Doesn’t it create an ambiguity? Instead of that probably giving all fields a prefix of “get_” like “get_position” would be much clearer?

The answer to the 2nd question sounds like this: field nodes are factories for creating functions. Their processing values belong to someone else. That’s what you get by using the position field or something like that.