What do these icons mean? GND?

Question

Electronics

What do these icons mean? (It seems to be according to ESKD)
And what is the difference between them?

Answer 1

you have to look at the diagram. in principle, the usual division into "types" of land.
lower, judging by the designation AGND, analog ground.
top - digital.
separated in low-noise circuits to shield the analog part from the noise of digital signals.
usually in the circuit both grounds are connected through an inductance so that the potentials are the same and the RF interference does not pass.