docs: clarify resource describes observed entity, not telemetry emitter

CHANGELOG.md

@@ -27,6 +27,10 @@ release.
 
 ### Resource
 
+- Clarify that a Resource describes the observed entity, not the component
+  that technically emits telemetry.
+  ([#4905](https://github.com/open-telemetry/opentelemetry-specification/pull/4905))
+
 ### Entities
 
 ### Common

specification/logs/data-model.md

@@ -170,7 +170,7 @@ Here is the list of fields in a log record:
 | SeverityText | The severity text (also known as log level). |
 | SeverityNumber | Numerical value of the severity. |
 | Body | The body of the log record. |
-| Resource | Describes the source of the log. |
+| Resource | Describes the observed entity that generated the log. |
 | InstrumentationScope | Describes the scope that emitted the log. |
 | Attributes | Additional information about the event. |
 | EventName | Name that identifies the class / type of event. |

specification/resource/README.md

@@ -23,15 +23,26 @@ path_base_for_github_subdir:
 
 ## Overview
 
-A Resource is a representation of the entity producing telemetry.
+A Resource represents the observed entity for which telemetry is produced.
 Within OpenTelemetry, all signals are associated with a Resource, enabling
 contextual correlation of data from the same source.  For example, if I see
-a high latency in a span I need to check the metrics for the same entity that
-produced that Span during the time when the latency was observed.
+a high latency in a span, I need to check the metrics for the same entity
+during the time when the latency was observed.
+
+> [!NOTE]
+> The entity that *technically emits* telemetry and the entity *described by*
+> a Resource are not always the same. In auto-instrumentation scenarios, such
+> as eBPF-based agents that observe a running process without code changes,
+> the instrumentation agent produces the telemetry on behalf of the observed
+> workload. In these cases, the Resource describes the *observed* entity
+> (e.g., the service or process being instrumented), not the agent itself.
+> Attributes such as `telemetry.sdk.name` and `telemetry.distro.name` that
+> pertain to the instrumentation tooling should be applied according to their
+> own semantic conventions rather than used to identify the observed entity.
 
 Resource provides two important aspects for observability:
 
-- It MUST identify an entity that is producing telemetry.
+- It MUST identify the observed entity for which telemetry is being produced.
 - It SHOULD allow users to determine where that entity resides within their infrastructure.
 
 ### Identity

specification/resource/data-model.md

@@ -18,13 +18,15 @@ weight: 2
 
 </details>
 
-A Resource is a representation of the entity producing telemetry as Attributes.
-For example, You could have a process producing telemetry that is
-running in a container on Kubernetes, which is associated to a Pod running on a
-Node that is a VM but also is in a namespace and possibly is part of a
+A Resource represents the observed entity for which telemetry is produced.
+It is defined by a set of Attributes that identify the source of the telemetry,
+rather than the component that technically produces it (like an
+auto-instrumentation agent).
+For example, a process running in a container on Kubernetes is associated to a
+Pod running on a Node that is a VM, in a namespace, and possibly part of a
 Deployment. Resource could have attributes to denote information about the
 Container, the Pod, the Node, the VM or the Deployment. All of these help
-identify what produced the telemetry. Note that there are certain attributes
+identify the observed entity. Note that there are certain attributes
 that have prescribed meanings.
 
 A resource is composed of 0 or more [`Entities`](../entities/README.md) and 0

specification/resource/sdk.md

@@ -7,12 +7,13 @@ weight: 3
 
 **Status**: [Stable](../document-status.md) except where otherwise specified
 
-A [Resource](../overview.md#resources) is an immutable representation of the entity producing
-telemetry as [Attributes](../common/README.md#attribute).
-For example, a process producing telemetry that is running in a
-container on Kubernetes has a Pod name, it is in a namespace and possibly is
-part of a Deployment which also has a name. All three of these attributes can be
-included in the `Resource`. Note that there are certain
+A [Resource](../overview.md#resources) is an immutable representation of the
+observed entity for which telemetry is being produced, expressed as
+[Attributes](../common/README.md#attribute).
+For example, a process running in a container on Kubernetes has a Pod name, it
+is in a namespace and possibly is part of a Deployment which also has a name.
+All three of these attributes can be included in the `Resource`. Note that there
+are certain
 [attributes](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/resource/README.md)
 that have prescribed meanings.