The process of converting alternating current into direct current is known as
A p-n junction can conduct current only when it is forward biased and does not while it is reverse biased.
A p-n junction is generally called a p-n junction diode since the current flows in an unidirectional manner and hence makes the diode suitable to used as a rectifier.
A rectifier converts alternating current to direct current and this process of converting AC to DC is known as rectification.