Biquad vs Cantenna

First let me say, I'm still in the reading phase with no hands on experience.

My question has to do with the continuity of the cable between the "closed" continuity of the biquad and the "open" using a cantenna.

The cantenna center element never touches the ground of the shielding, but the biquid seems to make the circuit since the element is soldered to the center element and the shielding.

Am I reading this correctly? Can an antenna use either?

yes, but... it depends on the length of the antenna

the cantenna is a quarter wave dipole in a container. the quarter wave dipole is essentially a capacitor.

the quad - is a half wave antenna, essentially a folded dipole pulled into a square. it is connected across both leads

a biquad is two quads