A digital garden is a means of distribution for Learning in public. It is a website that sits between offline notes and polished, performative written pieces.
I have found it to be mostly software developers who practice digital gardening. They understand from open sourced software culture that shared solutions, and sharing your own solutions, create a better whole, so they share openly along the way. Writing isn’t their main thing, but they know how to publish things online.
There are non-devs that practice learning in public, but a digital garden is not the main means for distribution. Podcasts and streaming work well for them.
A Brief History & Ethos of the Digital Garden (by Maggie Appleton) gives a great overview.
See My digital garden is a garage, not a garden for my spin on a digital garden.
I also like a related term: digital farming from The Garden and the Stream (by Mike Caulfield). A term to describe the dream state of the web.
Sometimes digital gardens double as a personal site.