What are the major ratings for junction diodes?

When selecting a junction diode for a circuit, especially in power supplies and rectification, the two most critical specifications are its maximum forward current and its peak inverse voltage (PIV). The maximum forward current rating indicates how much continuous current the diode can conduct safely in the forward direction without overheating and failing. The peak inverse voltage (PIV) specifies the absolute maximum reverse voltage the diode can withstand before it breaks down and allows current to flow in the wrong direction. Together, these two ratings define the safe operating boundaries of the diode. While characteristics like capacitance and reverse leakage current are important for specialized RF or precision circuits, forward current and PIV are the primary, major ratings for general junction diodes.