It is used 67 times in the NT. 16 times it refers to a church leader.
Acts 11:30 sending their gift to the elders
Acts 14:23 Paul and Barnabas appointed elders for them in each church
Acts 15:2,4,22,23,16:4 the apostles and elders
Acts 20:17 sent to Ephesus and called to him the elders of the church
Acts 21:18 all the elders were present
1 Tim. 4:14 the body of elders laid their hands on you.
1 Tim. 5:17 The elders who direct the affairs of the church well are worthy of double honor
1 Tim. 5:19 Do not entertain an accusation against an elder unless
Titus 1:5 appoint elders in every town, as I directed you
James 5:14 call the elders of the church to pray over him
1 Peter 5:1 To the elders among you, I appeal as a fellow elder

Acts 20:28 of which the Holy Spirit has made you overseers
Philippians 1:1 with the overseers and deacons
1 Timothy 3:2 the overseer must be above reproach
Titus 1:7 an overseer is entrusted with God's work
1 Timothy 3:1 if any man aspires to the office of overseer
1 Peter 5:2 exercising oversight

Ephesians 4:11 and some to be pastors and teachers
Acts 20:28 Be shepherds of the church
1 Peter 5:2 Be shepherds of God's flock that is under your care.

Hebrews 13:7 Remember your leaders
Hebrews 13:17 Obey your leaders and submit to their authority
Hebrews 13:24 Greet all your leaders and all God's people
1 Thessalonians 5:12 appreciate those who diligently labor among you, and have charge over you in the Lord
1 Timothy 5:17 Let the elders who rule well

Scriptural requirements are found in 1 Timothy 3:1-7 and Titus 1:5-9, as well as several other places – a quick list:
above reproach - 1 Timothy 3:2; Titus 1:7.
the husband of one wife - 1 Timothy 3:2; Titus 1:6.
temperate - 1 Timothy 3:2
sober-minded - 1 Timothy 3:2; Titus 1:8.
of good behavior - 1 Timothy 3:2.
hospitable - 1 Timothy 3:2; Titus 1:8.
a lover of what is good - Titus 1:8.
able to teach - 1 Timothy 3:2; Titus 1:9.
not given to wine - 1 Timothy 3:3; Titus 1:7
not violent - 1Timothy 3:3; Titus 1:7.
gentle - 1 Timothy 3:3; 2 Timothy 2:24.
not quick-tempered - Titus 1:7; James 1:19-20.
not quarrelsome - 1 Timothy 3:3; 2 Timothy 2:24-26; James 3:13-18 .
Just - Titus 1:8
holy - Titus 1:8.
self-controlled - Titus 1:8.
not covetous - 1 Timothy 3:3; Titus 1:7; 1 Peter 5:2.
one who rules his own house well - 1 Timothy 3:4; Titus 1:6
having his children in submission with all reverence - 1 Timothy 3:4-5; Titus 1:6.
not a novice - 1 Timothy 3:6.
have a good testimony among those who are outside - Timothy 3:7.
must serve, not by compulsion, but willingly; eagerly - 1 Peter 5:2; 1 Timothy 3:1.
not self-willed - Titus 1:7; 1 Peter 5:3.
an example to the flock: - 1 Peter 5:3; Titus 2:7

1 Peter 5:2 - Be shepherds of God's flock that is under your care, serving as overseers-not because you must, but because you are willing

Ephesians 4:12 - for the equipping of the saints for the work of ministry

1 Timothy 5:17 - whose work is preaching and teaching.
1 Timothy 3:2 - able to teach

Titus 1:9-11, Acts 20:28-31, 1 Peter 5:1-2, 1 Thess. 5:12-14

James 5:14 - call the elders of the church to pray over him

1 Peter 5:3 - being examples to the flock Ordain others

1 Timothy 4:14 - with the laying on of the hands of the eldership

The Desire of the man
1 Timothy 3:1 - It is a trustworthy statement: if any man aspires to the office of overseer, it is a fine work he desires to do.

The Conviction of existing leadership/elders
Titus 1:5 - appoint elders
Acts 14:23 - Paul and Barnabas appointed elders for them in each church
Acts 6:3 - But select from among you, brethren

While members of the pastoral staff may serve as elders, it is clear from Scripture that elders were selected from those within the church, not brought in from another place.

Acts 14:23 Paul and Barnabas appointed elders for them in each church
Titus 1:5 appoint elders in every town, as I directed you

in a biblical perspective, probably nothing, again, the titles are interchangeable. A pastor in a church, whether they be senior, associate, youth, children’s, sports, are overseers of those ministries. A pastor may serve as an elder in the church; however, it is not always the case. Elders are from within, many times, pastoral staff is from without. The only pastoral position that is an elder by default is the Senior Pastor, who serves as the chairman of the Leadership Team, however, like the other members, is given an equal vote on all issues, and serves as the deadlock vote as well.

Pastors are paid, ideally, for their service; Elders are unpaid for their services.

According to 1 Timothy 3, a distinction is made in both title and responsibility. The elder is to teach and lead while the deacon (diakonos) is to serve. The scriptural qualifications for each position are very similar with the only difference in that an elder must be gifted to teach.

Each Community (small group) will have someone that serves the role of deacon within it. To take care of and facilitate meeting the needs of members.

1. In following Scripture, a church will be blessed.
2. There is a plurality of leadership, not just in hands of one person.
3. After pastor resigns or is removed, there is constant, on-site leadership during the interim.
4. With mutual submission of elders, there is true accountability over pastor, a church is protected from a pastor that is teaching false doctrine, unethical, or problematic.
5. More complete leadership with plurality of leaders, inadequacies and weaknesses are covered by others.
6. There is a larger group of people recognized by the church to teach. It is part of what an elder is ordained to do.
7. There is no clerical hierarchy, leaders and ministers come out of the body.
8. A stream-lined process for decisions to be made.
9. More people are freed up to be involved in serving and ministering.
10. Church leaders are put into position by Biblical requirements, thus safe-guarding the church from those in leadership positions that are not spiritually qualified.
11. The church is blessed with godly leaders who pray to the Head of the (Church (Jesus Christ) about the direction of His church and then work together to bring this vision to the body.