Paul Carter, a Fellowship Pastor, writes for The Gospel Coalition Canada:
“This passage [Acts 20:7-28] is particularly helpful because it uses the word for elder, presbyteros, again in the plural form, as well as the word for overseer, episkopos, also in the plural, and the word for shepherd, poimainō, in the infinitive, which can also be translated “to pastor”[1]. The English word pastor is based on the Latin word pastor which means “shepherd”. The fact that Luke refers to the group of people addressed by Paul as “elders” in verse 17 and then subsequently as “overseers” in verse 28 indicates that these terms were considered synonymous: an elder was an overseer. That he connects the oversight office to the task of shepherding/pastoring in verse 28 suggests a tight connection between those concepts.”
…
“Collectively, these five passages suggest that the terms elder and overseer should be understood as synonyms, referring to the authoritative leadership office in the church tasked with leading, feeding and protecting the flock of God. These tasks are properly understood and described in shepherding or pastoral terms. In the same way that a shepherd has a rod so as to lead and defend the flock, so too the pastor/elder/overseer is invested with authority to care for, correct and if necessary corral a straying congregant. Further, the fact that the terms presbyteros, episkopos and poimēn, when used in noun form referring to human leaders other than Jesus, always appear in the plural suggests that a plurality of oversight leaders was the norm in New Testament churches.”
To read the entire article: https://ca.thegospelcoalition.org/columns/ad-fontes/is-a-pastor-the-same-thing-as-an-elder/