passive networks - Confused with electrostatic pickup and capacitive coupling terms

I can understand the meaning of capacitive coupling of the signal line to GND or Earth or nearby earthed objects. Below line section illustrates that:

But there is also a term called “electrostatic pickup”. I guess it means the same thing with above.(?)

And texts tell us if the signal is low, to prevent electrostatic pickup coaxial cables are used.

I don’t really understand why it is called electrostatic pickup. What is static here? Capacitors do not pass static current as well. Why does the coaxial cable prevent electric field but not magnetic field?

Im completely confused about the distinction even though I know what electric field and magnetic field means.

Some even claims that “Hi, to answer to you question, you must know that coaxial cable is not able to protect against low frequency EM disturbance, whatever its kind (magnetic/electric)”

Answer

In general usage, we think of electric fields and magnetic fields as separate things. (They're actually manifestations of the same underlying fundamental physical field.)

When interference is coupled primarily through electric fields, we use the term "electrostatic coupling", mainly to distinguish it from "electromagnetic coupling", or interference coupled primarily through magnetic fields. We also call it "capacitive coupling", because the operation of a capacitor is based on electric fields. We also call magnetic coupling "inductive coupling" for much the same reason — the operation of an inductor is based on magnetic fields.

Coaxial cable shows good resistance to both kinds of coupling.

It resists magnetic coupling by virtue of the fact that both the inner conductor and the outer conductor share a common axis (hence, the name), which means that magnetic fields will act on both equally. The only time that this fails is when the field has a strong gradient — meaning that the field is significantly different across the diameter of the cable. A length of coax running immediately parallel to a power cable carrying high current could experience such a gradient.

It resists electric coupling by virtue of the fact that the shield forms a complete conductive shell around the inner conductor. An electric field impinging on the outside of the shield cannot affect the field inside the shield. Therefore, we use the inner conductor to carry the signal and ground the shield. This fails only because the shield is not perfect — it has resistivity and/or it is not a solid conductor (twisted or braided wires rather than foil), and this allows some E-field penetration to the interior.