Groups are essentially permanent selection sets. In some way, they are similar to layers in the drawing.
You can organise groups according to your requirements. For example:
Existing pipes could be in one group, Phase 1 development in another, then Phase 2, Phase 3.
Bulk infrastructure could be structured as one group, reticulations for each suburb or village in separate groups.
A default group exists in every project, which cannot be deleted. Additional groups can be created or deleted as required, and elements can be freely moved between them.
A group can be made visible or invisible, and can be included in the hydraulic analysis or excluded from it.
All elements of the model belong to one or more groups. Newly created elements are included in the current group at the time of creation.