How does identity linking work in the Switch edu-ID, and why is the personal part called persistent while affiliations are transient?

Question

Accepted Answer

Every user owns a personal edu-ID account that lasts for life; when the user joins a university, an affiliation (an organisational identity such as HSLU or BFH) is linked to it. The personal part persists, the affiliations come and go with the person's memberships.

* One lifelong personal account, with organisational identities attached and detached as memberships change. *
The Switch edu-ID is the Swiss academic identity service. Its design separates two layers:

Personal part of the identity (persistent): the edu-ID account itself, created once by the person and kept across studies, jobs and institutions.
Affiliations (transient): organisational identities such as "employee at BFH" or "employee at HSLU", each with its own institutional e-mail address, linked to the account while the membership lasts and removed when it ends.

This solves a classic problem of university IT: students and staff used to lose their identity every time they changed institution. With edu-ID the identity is the person's, and institutions merely attach and detach affiliations, which is identity linking with a clear owner. The account overview literally lists "your account is linked with the following organisational identities".
Go deeper:

Switch edu-ID — the service itself: one lifelong login for Swiss higher education.