Quick junction / pn junction diode clarification
The junction is the area of the diode in the center where the P and N regions meet. In a silicon diode current is blocked at the junction if the voltage is reversed and typically for a forward voltage, the junction develops a .67 voltage drop. For any forward voltage greater than .67 volts, the junction conducts current.The P and N regions are always conductive within them selves, the junction conducts in one direction only.

Quote https://wiki.analog.com/university/courses/electronics/text/chapter-5:


  A p-doped semiconductor is relatively conductive. The same is true of an n-doped semiconductor, but the junction between p and n type regions is a nonconductor. This non-conducting layer, called the depletion layer, occurs because the electrically charged carriers, electrons in n-type and holes p-type silicon, diffuse into the other type of material (i.e. electrons in p-type and holes in n-type) and eliminate each other in a process called recombination. This diffusion of charge causes a built in potential difference across the depletion region. By manipulating this non-conductive layer, PN junctions are commonly used as diodes: circuit elements that allow a flow of electricity in one direction but not in the other (opposite) direction. This property is explained in terms of forward bias and reverse bias, where the term bias refers to the application of an electric voltage across the PN junction. A PN junction will conduct current when the applied external voltage exceeds the built in potential of the junction.