In a junction diode or transistor, majority charge carriers are the dominant type of charge carriers in a semiconductor, while minority charge carriers are present in smaller quantities. The depletion region contains immobile charges, which are fixed ions left behind when majority carriers leave the region, creating an electric field. This electric field prevents further movement of charge carriers across the junction, establishing a potential barrier. Understanding the behavior of these carriers is crucial for grasping how diodes and transistors function in electronic circuits. Clarifying specific processes or concepts can lead to a more detailed explanation.