A span is one timed operation in a trace, and how spans nest tells you the structure of a request.
A span is the basic unit of work in a distributed trace: a single named operation with a start and end time, a set of attributes, a status, and a link to its parent span. Spans nest to form a complete trace.
A span records a name (the operation), a start and end timestamp (its duration), attributes (key-value context such as the HTTP route or database statement), a status (ok or error), and references to its parent and trace. Events and links can add further detail.
The first span in a request is the root span; every operation it triggers becomes a child span, and children can have their own children. This parent-child nesting is what turns a flat list of operations into a tree that shows how a request fanned out and where the time went.
Sentinel AI reads span attributes and status when it investigates, using the error span and its parent chain to localise a fault to a specific operation.
The root span is the first span in a trace, representing the entry point of the request; all other spans in that trace descend from it.
Key-value pairs that add context to a span, such as http.request.method or db.system, following OpenTelemetry semantic conventions so they are consistent across tools.
Ops Singularity turns open telemetry into autonomous, governed resolution. See it on your own stack.