Answer:
The role bishops played in the early Christian Church was to manage churches and take care of several congregations.
The role priests played in the early Christian church was to officiate the Eucharist as delegates.
Step-by-step explanation:
In the early Christian Church, a bishop was the main minister and manager of churches of the area in which they were assigned to. All this, because the bishops were successors of the apostles.
The priests' duties were mainly connected to the celebration of the Eucharist even though priesthood was a job done by bishops and the elders. The fact that the first bishops outsource the realization of the eucharist to some other presbyter ended up creating the notion of the priest as such.