upstreams

Upstreams generally denote sources or origins in a system, referring to directions toward the source of a river, or to the principal or original version of a project. In technology contexts, the term is used to denote the official project from which other copies derive.

In software development and version control, an upstream repository is the main project repository where the official code resides. Forks and clones create a local or forked copy. Contributors fetch or pull from upstream to integrate new changes, and may push changes to their own forks or branches. Maintainers use the term to indicate where changes should flow back, e.g., submitting patches to the upstream repository. Common workflows involve syncing with upstream, resolving conflicts, and ensuring compatibility with the upstream codebase.

In rivers and hydrology, upstream refers to the direction toward the source or headwaters. It is the opposite of downstream. Water quality, sediment transport, and ecological patterns are often described relative to upstream or downstream.

In networking and computing, upstream can describe traffic moving from a client toward the network core or toward an upstream service provider, while downstream describes traffic toward end users. In this sense, bandwidth, latency, and routing can be described as upstream or downstream.

In biology and biochemistry, upstream denotes earlier steps in a pathway or regulatory cascade, often indicating control points that influence downstream processes.