Player groups
A group represents a collection of musicians that are considered together, such as a choir, orchestra, or chamber ensemble.
Grouping players together means they are positioned together in the score, numbered independently, and are bracketed together according to the project template.
For example, if your project is for double choir (SATB/SATB), all voices are joined by a single bracket by default because they are in the same family. However, if you add each choir to its own group, they are bracketed separately. This is useful for to bracket players properly in works containing multiple groups, such as in Britten's War Requiem, which has three distinct groups, or in Walton's Belshazzar's Feast which requires two separate off-stage brass groups.
Similarly, you can create a group for an off-stage group of players in a large-scale work.
If the instruments were not already next to each other according to orchestral order, adding a player group changes the order of players in the score project-wide.