# A data model for describing demographic histories.

The Demes specification defines a data model for describing one or
more demes (also known as populations), how they change over time, and their
relationships to one another. A human-readable Demes model is written
as a YAML file, which facilitates model sharing, reuse, and interoperability.

# Documentation

Users interested in learning how to read and/or write a Demes YAML file
are referred to the tutorial in the
[Demes documentation](https://popsim-consortium.github.io/demes-spec-docs/).
A more precise definition of the Demes specification can also be found in
the documentation, in the form of an annotated schema.

# Software

Software for working with Demes YAML files is located in external repostories.
In particular, the
[`demes` Python package](https://github.com/popsim-consortium/demes-python).
Links to additional Demes-related software can be found in the documentation.