RabbiThere are a variety of professionals who work full time and part time at a synagogue, and many others who volunteer their services.
In addition, depending upon the size of the congregation and the extent of their programing, synagogues hire administrators, secretaries, teachers, and custodians.
Rabbi"Rabbi" means "teacher" and, through preaching from the pulpit, teaching classes, and individual counseling, teaching is the primary duty of a rabbi. In addition, many rabbis serve as administrators of their synagogues, represent the congregation to the community, officiate at life-cycle events, and serve as Jewish legal decisors (that is, they render decisions concerning Jewish legal matters that come before them). Each of the Jewish movements in America sponsors a seminary for the training of rabbis, which is a lengthy program.
Cantor/ChazzanTraditionally, a Jewish prayer service is chanted. The leader is called the shaliach tzibbur (the representative of the community) who recites the prayers on behalf of the people. Some prayers are said by everyone, and some are recited aloud by the shaliach tzibbur, to which the congregation responds "Amen." The chazzan (cantor) is specially trained in the art of Jewish music and liturgy for this role. In many congregations, the cantor is professionally trained and studies a broad pallet of Jewish subjects in addition to those mentioned above, and does a good deal of teaching, counseling, and life-cycle officiation in addition to leading the community in prayer.
Often, a congregation hires a Jewish educator to run its religious school program, and perhaps its adult education program as well. Often, a rabbi or cantor combines this role with other duties.
The shammas is the one who takes care of the physical plant of the synagogue. Many congregations hire custodians these days, because the needs of the community warrant it. In small congregations, a member may volunteer to take on these responsibilities. The shammas is also known by the terms beadle or sexton.
If you attend services on a day when the Torah is read publicly, you may well see two people standing on either side of the reading table while the Torah is read, who assist the reader and make sure that the Torah Service runs smoothly. These people are the gabbaim. It is their job to call people to the Torah for their aliyot, check that the reader makes no mistakes while reading the Torah, and provide correction if a mistake is made, recites the Mi Sheberach for those who have had an aliyah, and see to the mechanics of covering and uncovering the Torah scroll at the appropriate times. Usually, the gabbaim are congregants who possess the skills to fulfill these tasks.
After the Torah has been read, the congregation will be asked to stand and someone will lift the scroll above his/her head. This person will then turn around so that the side of the scroll with the writing faces the congregation, and turn as necessary to enable everyone assembled to view the scroll, since not everyone received the honor of an aliyah, thereby enabling them to peer into the scroll that morning. It is traditional to show a minimum of three columns of writing, including the portion read that morning. The honor of lifting the Torah is called hagbah. The person honored with lifting the torah is referred to as the hagbahah.
After the congregation has had an opportunity to see the scroll, the hagbahah sits in a chair on the bima and the another person, who is being honored with gelilah, the rolling and dressing of the scroll, comes forward. The person honored with gelilah ties the sash around the scroll, places the mantle over the scroll, and puts on the breastplate and crown. (For a description of these items, click here.)