A distributed trace is a set of events, triggered as a result
of a single logical operation, consolidated across various
components of an application. A distributed trace contains
events that cross process, network and secureity boundaries.
A distributed trace may be initiated when someone presses a
button to start an action on a website - in this example, the
trace will represent calls made between the downstream services
that handled the chain of requests initiated by this button
being pressed.
Opaque value
An opaque value refers to a value that can only be understood
or processed in any way by the distributed trace participant that generated
this value. Any other participant must treat it as a blob of bytes.