[DOCUMENTATION] Update terms in documentation #448

docs/user/terms.rst

@@ -5,41 +5,55 @@ Glossary
 
     digraph {
       rankdir=RL;
-      { Service Prometheus} -> Shard;
       { Rule Notifier Project} -> Service;
+      { Project Prometheus} -> Shard;
       { Rule Notifier Exporter URL Farm} -> Project;
       Host -> Farm;
-      { rank=same Project Rule };
+      { rank=same Notifier Rule };
    }
 
 
 Shard
 -----
 
-Shards are the top level object in Promgen which contain both Services and
-Prometheus servers
+Shards are a collection of Prometheus servers monitoring the same targets.
 
 Service
 -------
 
-A service in Prometheus is a group of related Projects and are assigned to a
-specific shard
+A service in Promgen is a group of related Projects and Rules.
+Service is typically the top-level object in Promgen.
 
 Projects
 --------
 Projects are one of the main groupings for Promgen. This represents a typical
 monitoring target and brings together a collection of servers (Farm) with
-Exporters and URL endpoints
+Exporters and URL endpoints. They are assigned to a Shard.
 
 Farm
 ----
-Farm is a group of servers. Farms may be updated using :doc:`discovery plugins </plugin/discovery>`
+Farm is a group of servers. Farms may be updated using :doc:`discovery plugins </plugin/discovery>`.
 
 Notifiers
 ---------
 :doc:`Notifiers </plugin/notification>` are used for routing messages to a specific destination such as Email or
-LINE Notify
+LINE Notify.
+They can be assigned to either a Project or a Service, watching for alerts that match that label.
 
 Rule
 ----
-Rules represent the rules that Prometheus itself uses for alerting
+Rules represent the rules that Prometheus itself uses for alerting.
+They can be assigned to a Project, or assigned to a parent Service that covers multiple Projects.
+
+Exporter
+--------
+
+These correspond to `Prometheus exporters`_ and other monitoring integrations.
+
+URL
+---
+
+These are URLs that are monitored via `blackbox_exporter`_
+
+.. _Prometheus exporters:  https://prometheus.io/docs/instrumenting/exporters/
+.. _blackbox_exporter:  https://github.com/prometheus/blackbox_exporter