# 3.4. Sources

This section discusses the volumetric source terms, as defined in Equations Aria Solves for each equation Aria solves. This term may vary in space and time, and is defined piecewise over each subdomain . Physically, this term corresponds to the production rate of the conserved quantity .

Note that this section is not a comprehensive list of all sources available in Aria, but is rather a subset of representative sources that are commonly used. Details on what a specific source applies can be found in its command summary.