A tribute band or act should not to be confused with cover band or act. Let’s see what Wikipedia has to say:
Tribute band or act
A tribute act is a music group, singer, or musician who specifically plays the music of a well-known music act – sometimes one which has disbanded, ceased touring or is deceased. Most tribute acts are groups (tribute band or tribute group) and are tributes to a group.
A tribute band does not include members of the original band whose music is being honored. If a member is included in a band performing the music of their original group, the band is seen as a spin-off band rather than a tribute band. However, guest appearances do occur.
Tribute bands usually name themselves based on the original band’s name, some song and even albums (e.g. Killer Queen).
Cover band or act
A cover band (or covers band), is a band that plays mostly or exclusively cover songs. New or unknown bands often find the cover band format marketable for smaller gigs, and these bands may be known as a wedding band, party band and function band. A band whose covers consist mainly of songs that were chart hits is often called a top 40 band. Many bands, however, start as cover bands and then grow to perform original material.
The main way in which a tribute band differs from a cover band that simply plays songs by other artists, is that it strives to capture every nuance of the imitated artist’s actions and appearance for a perfect imitation. Some tribute bands imitate the appearance but re-interpret the original works in a particular genre or for comic effect. For example, Dread Zeppelin plays Led Zeppelin songs in a reggae style with a lead singer dressed up as Elvis Presley, Gabba perform the songs of ABBA in the style of The Ramones and Queen Unplugged Project plays Queen acoustically. There are also individuals who are tributes of a group, and vice versa.
See the List of Queen tribute bands