Document navigation & information architecture objects/terminology within conceptual model
# Problem
- With more stages working on features that span across different groups, or don't map to projects/groups at all (Basically, anything in the more menu), we need to be clear on which level of the product's information architecture that we are working on - between ourselves and with our users.
- I have been using the term `Instance` to refer to the scope of data across all groups - as well as areas which don't actually align with our project/group architecture.
- To others, `Instance` is an installation of GitLab and means something very specific.
- There is also work to consolidate these organisational constructs later on: https://gitlab.com/groups/gitlab-org/-/epics/2885
- See example confusion here: https://gitlab.com/gitlab-org/gitlab/-/issues/276912#note_445437331
# Proposal
1. Agree on correct terminology and document in Pajamas
1. Map & document conceptual models for:
- Instance (or other name)
- Group / sub-group
- Project
# Links
- [Object model napkin sketch](https://www.youtube.com/watch?v=GMCS1sBzw9I)
- Pedro's work on issuable conceptual model: https://gitlab.com/gitlab-org/gitlab-design/-/issues/1222
- Navigation vision: https://gitlab.com/gitlab-org/gitlab/-/issues/255325
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