According to Paul Scherz in his Practical Electronics for Inventors, he mentions in Chapter 2, Theory, the following:
Typically, the earth, with its infinite charge-absorbing ability and net zero charge, acts as a good point for comparison. It is considered the $0-V$ reference point or ground point.
I thought that ground in any circuit was a point in the circuit with respect to which other voltages were measure. And it was literally the connection to the earth (for safety purposes in house wirings, etc.) that earth meant.
But the text suggests that I’m wrong.
I just want to know what is correct.