Improve wording and structure in overview doc.

content/docs/introduction/overview.md

@@ -10,49 +10,62 @@ sort_rank: 1
 [Prometheus](https://github.com/prometheus) is an open-source systems
 monitoring and alerting toolkit built at [SoundCloud](http://soundcloud.com).
 Since its inception in 2012, it has become the standard for instrumenting new
-services at SoundCloud and has seen growing external usage and contributions.
-Prometheus's main distinguishing features are:
+services at SoundCloud and is seeing growing external usage and contributions.
 
-- a **multi-dimensional** data model (time series identified by metric name and key/value pairs)
-- a [**flexible query language**](/docs/using/querying/basics/)
+### Features
+
+Prometheus's main features are:
+
+- a multi-dimensional [data model](/docs/concepts/data_model/) (time series identified by metric name and key/value pairs)
+- a [flexible query language](/docs/using/querying/basics/)
   to leverage this dimensionality
-- no reliance on distributed storage; **single server nodes are autonomous**
-- time series collection happens via a **pull model** over HTTP
-- **pushing time series** is supported via an intermediary gateway
-- targets are discovered via **service discovery** or **static configuration**
-- multiple modes of **graphing and dashboarding support**
+- no reliance on distributed storage; single server nodes are autonomous
+- time series collection happens via a pull model over HTTP
+- [pushing time series](/docs/instrumenting/pushing/) is supported via an intermediary gateway
+- targets are discovered via service discovery or static configuration
+- multiple modes of graphing and dashboarding support
+
+### Components
 
 The Prometheus ecosystem consists of multiple components, many of which are
 optional:
 
 - the main [Prometheus server](https://github.com/prometheus/prometheus) which scrapes and stores time series data
-- client libraries for instrumenting application code
+- [client libraries](/docs/instrumenting/clientlibs/) for instrumenting application code
 - a [push gateway](https://github.com/prometheus/pushgateway) for supporting short-lived jobs
-- a [GUI-based dashboard builder](PromDash) based on Rails/SQL
-- special-purpose exporters (for HAProxy, StatsD, Ganglia, etc.)
+- a [GUI-based dashboard builder](/docs/visualization/promdash/) based on Rails/SQL
+- special-purpose [exporters](/docs/instrumenting/exporters/) (for HAProxy, StatsD, Ganglia, etc.)
 - an (experimental) [alert manager](https://github.com/prometheus/alertmanager)
 - a [command-line querying tool](https://github.com/prometheus/prometheus_cli)
 - various support tools
 
+### Architecture
+
 This diagram illustrates the overall architecture of Prometheus and some of
 its ecosystem components:
 
 ![Prometheus architecture](/assets/architecture.svg)
 
+Prometheus servers scrape metrics from instrumented jobs, either directly or
+via an intermediary push gateway for short-lived jobs. They store all scraped
+samples locally and run rules over this data to either record new timeseries
+from existing data or generate alerts. PromDash or other API consumers can be
+used to visualize the collected data.
+
 ## When does it fit?
 
-Prometheus works well both for machine-based monitoring as well as monitoring
-of highly dynamic service-oriented architectures. In a world of microservices,
-its support for multi-dimensional data collection and querying is a particular
-strength.
+Prometheus works well for recording any purely numeric time series. It fits
+both machine-centric monitoring as well as monitoring of highly dynamic
+service-oriented architectures. In a world of microservices, its support for
+multi-dimensional data collection and querying is a particular strength.
 
 Prometheus is designed for reliability, to be the system you go to
 during an outage to allow you to quickly diagnose problems. Each Prometheus
 server is standalone, not depending on network storage or other remote services.
-You can rely it when other parts of your infrastructure are broken, and
+You can rely on it when other parts of your infrastructure are broken, and
 you don't have to set up complex infrastructure to use it.
 
-## When doesn't it fit?
+## When does it not fit?
 
 Prometheus values reliability. You can always view what statistics are
 available about your system, even under failure conditions. If you need 100%