The personal data server stores the repository, the signing keys and usually a rotation key, answers the user's app, proxies to services, signs and publishes commits, and can be self-hosted under your own domain.

The PDS is the one server you must trust, and you can be it.

Your personal data server is your home in the cloud. It stores your repository and holds your signing keys. Usually a rotation key too, unless you keep your own.

It answers your app's requests, and forwards the ones meant for other services.

Every change you make, it signs and publishes as a commit.

You can run one yourself, on a small server, under your own domain. It joins the same network as everyone else.

A host is a home, not a walled garden. Thousands of hosts. One network.

Check yourself. Which two things does a PDS always store?