The leadership and decision-making body of the local congregation of every PC(USA) church is called the session. Each session is comprised of at least one "teaching elder", or minister, who acts as a moderator for the group, and representative members of the population of that congregation.
Being a member of the session is truly a call from the Holy Spirit. It requires prayerful decision-making and a good amount of hard work, but the rewards are immeasurable. If you are asked to become an elder please ask the Lord to guide you in your decision. If you do decide to accept the call, remember that your primary purpose as an elder in the church is "...to provide opportunities for evangelism to be learned and practiced in and by the church, that members may be better equipped to articulate their faith, to witness in word and deed to the saving grace of Jesus Christ, and to invite persons into a new life in Christ".