The terms “servers”, “altar servers” and “ministers” and used in the 2002 General Instruction of the Roman Missal (GIRM) approved for the USA, which can be accessed from
romanrite.com/girm.html :
“150. A little before the consecration, when appropriate, a
server rings a bell as a signal to the faithful. According to local custom, the
server also rings the bell as the priest shows the host and then the chalice.
If incense is used, a
server incenses the host and the chalice when each is shown to the people after the consecration.”
“175. … He is preceded by a thurifer, carrying a thurible with smoking incense, and by
servers with lighted candles. …”.
“339. In the dioceses of the United States of America, acolytes,
altar servers, lectors, and other lay ministers may wear the alb or other suitable vesture or other appropriate and dignified clothing.”
The term “ministers” is used most frequently, 50 times. Some examples:
“44. Among gestures included are also actions and processions: of the priest going with the deacon and
ministers to the altar; …”
“100. In the absence of an instituted acolyte, lay
ministers may be deputed to serve at the altar and assist the priest and the deacon; …”.
“120. … b. The
ministers who carry lighted candles, and between them an acolyte or other minister with the cross;”.
“133. If the Book of the Gospels is on the altar, the priest then takes it and goes to the ambo carrying the Book of the Gospels slightly elevated and preceded by the lay
ministers, who may carry the thurible and the candles.”
So “minister” here does not mean someone ordained, or someone instituted (see n. 100 above).
The term “liturgical ministers” is not used in the GIRM.