Episkopos appears 5 times in the NT (Acts 20:28; Philippians 1:1; 1 Timothy 3:2; Titus 1:7; 1 Peter 2:25). The word comes from epi (over) + skopos (watcher, one who looks), meaning 'one who looks over, oversees.' In the Greek world it was used for inspectors, supervisors, and guardians. In the NT, it describes church leaders responsible for pastoral oversight. 1 Peter 2:25 applies it to Christ himself: 'the Shepherd and Overseer [episkopon] of your souls.' The qualifications for an episkopos in 1 Timothy 3:1-7 are detailed and character-centered.
The relationship between episkopos (overseer/bishop) and presbyteros (elder) in the NT is debated. In Acts 20:17, 28, Paul summons the 'elders' (presbyterous) of Ephesus and then describes their function as 'overseers' (episkopous) — suggesting the same people are described by both terms. Titus 1:5-7 moves directly from appointing 'elders' to listing qualifications for the 'overseer.' This suggests that in the NT period, the two terms overlapped significantly, with distinct mono-episcopacy (one bishop over a region) developing later in church history. What is clear is that the episkopos role was one of responsible shepherding, not hierarchical power.