the meaning of observation point

Hi,
if I define a single borehole, and I add an observation point in the node which I define it as the BHE before, what is the meaning of the observation point temperature? if it represent the borehole, why the temperature of that point is not equal to the temperature of the output of borehole?
Could anybody help me ? I am very confused ?
Thank you a lot for your kindly help .
lemon

The observation point represents the soil temperature at this point, which is not equal to the temperature within the borehole.