Improve dashboard documentation (part 2) (#11065)

* Finish initial draft

* Finish with draft of installation flow

* Change analytics path

* Rename file and improve flow

* Init new files

* Init new dashboard files

* Init new file

* Finish revising existing docs

* Finish initial draft

* Finish with draft of installation flow

* Change analytics path

* Rename file and improve flow

* Init new file

* Finish revising existing docs

* Fix link

* Tweak on contexts for Thiago

* Clarify dimension values and units

* Tweaks for Ilya

5 files changed, 182 insertions, 7 deletions

diff --git a/docs/dashboard/dimensions-contexts-families.mdx b/docs/dashboard/dimensions-contexts-families.mdx
new file mode 100644
index 0000000000..6e401d4928
--- /dev/null
+++ b/docs/dashboard/dimensions-contexts-families.mdx
@@ -0,0 +1,92 @@
+---
+title: "Chart dimensions, contexts, and families"
+description: "Netdata organizes charts into dimensions, contexts, and families to automatically and meaningfully organize thousands of metrics into interactive charts."
+type: explanation
+custom_edit_url: https://github.com/netdata/netdata/edit/master/docs/dashboard/dimensions-contexts-families.mdx
+---
+
+# Chart dimensions, contexts, and families
+
+While Netdata's charts require no configuration and are [easy to interact with](/docs/dashboards/interact-charts.mdx),
+they have a lot of underlying complexity. To meaningfully organize charts out of the box based on what's happening in
+your nodes, Netdata uses the concepts of **dimensions**, **contexts**, and **families**. 
+
+Understanding how these work will help you more easily navigate the dashboard, [write new
+alarms](/docs/monitor/configure-alars.md), or play around with the [API](/web/api/README.md).
+
+For a refresher on the anatomy of a chart, see [dashboards and charts](/docs/dashboards/dashboards-charts.mdx).
+
+## Dimension
+
+A **dimension** is a value that gets shown on a chart. The value can be raw data or calculated values, such as the
+average (the default), minimum, or maximum. These values can then be given any type of unit. For example, CPU
+utilization is represented as a percentage, disk I/O as `MiB/s`, and available RAM as an absolute value in `MiB` or
+`GiB`.
+
+Beneath every chart (or on the right-side if you [configure the
+dashboard](/docs/dashboards/customize.mdx#change-chart-legend-position)) is a legend of dimensions. When there are
+multiple dimensions, you'll see a different entry in the legend for each dimension.
+
+The **Apps CPU Time** chart (with the [context](#contexts) `apps.cpu`), which visualizes CPU utilization of
+different types of processes/services/applications on your node, always provides a vibrant example of a chart with
+multiple dimensions.
+
+![An example apps.cpu chart with many
+dimensions](https://user-images.githubusercontent.com/1153921/114207816-a5cb7400-9911-11eb-8800-06f60b745f9c.png)
+
+The chart shows 13 unique dimensions, such as `httpd` for the CPU utilization for web servers, `kernel` for anything
+related to the Linux kernel, and so on. In your dashboard, these specific dimensions will almost certainly be different.
+
+Dimensions can be [hidden](/docs/dashboards/interact-charts.mdx#show-and-hide-dimensions) to help you focus your
+attention.
+
+## Context
+
+A **context** is a way of grouping charts by the types of metrics collected and dimensions displayed. It's kind of like
+a machine-readable naming and organization scheme.
+
+For example, the **Apps CPU Time** has the context `apps.cpu`. A little further down on the dashboard is a similar
+chart, **Apps Real Memory (w/o shared)** with the context `apps.mem`. The `apps` portion of the context is the **type**,
+whereas anything after the `.` is specified either by the chart's developer or by the [**family**](#family). 
+
+By default, a chart's type affects where it fits in the menu, while its family creates submenus.
+
+Netdata also relies on contexts for [alarm configuration](/docs/monitor/configure-alarms.md) (the [`on`
+line](/health/REFERENCE.md#alarm-line-on)).
+
+## Family
+
+**Families** are a _single instance_ of a hardware or software resource that needs to be displayed separately from
+similar instances.
+
+For example, let's look at the **Disks** section, which contains a number of charts with contexts like `disk.io`,
+`disk.ops`, `disk.backlog`, and `disk.util`.  If your node has multiple disk drives at `sda` and `sdb`, Netdata creates
+a separate family for each.
+
+Netdata now merges the contexts and families to create charts that are grouped by family, following a
+`[context].[family]` naming scheme, so that you can see the `disk.io` and `disk.ops` charts for `sda` right next to each
+other.
+
+Given the four example contexts, and two families of `sda` and `sdb`, Netdata will create the following charts and their
+names:
+
+| Context        | `sda` family       | `sdb` family       |
+| :------------- | ------------------ | ------------------ |
+| `disk.io`      | `disk_io.sda`      | `disk_io.sdb`      |
+| `disk.ops`     | `disk_ops.sda`     | `disk_ops.sdb`     |
+| `disk.backlog` | `disk_backlog.sda` | `disk_backlog.sdb` |
+| `disk.util`    | `disk_util.sda`    | `disk_util.sdb`    |
+
+## What's next?
+
+With an understanding of a chart's dimensions, context, and family, you're now ready to dig even deeper into Netdata's
+dashboard. We recommend looking into [using the timeframe selector](/docs/dashboards/select-timeframes.mdx).
+
+If you feel comfortable with the [dashboard](/docs/dashboard/how-dashboard-works.mdx) and interacting with charts, we
+recommend learning about [configuration](/docs/configure/nodes.md). While Netdata doesn't _require_ a complicated setup
+process or a query language to create charts, there are a lot of ways to tweak the experience to match your needs.
+
+### Further reading & related information
+
+- [How the dashboard works](/docs/dashboard/how-dashboard-works.mx)
+- [Interact with charts](/docs/dashboard/interact-charts.mdx)
diff --git a/docs/dashboard/how-dashboard-works.mdx b/docs/dashboard/how-dashboard-works.mdx
index 1c0e2bdd99..64887e84b8 100644
--- a/docs/dashboard/how-dashboard-works.mdx
+++ b/docs/dashboard/how-dashboard-works.mdx
@@ -95,7 +95,9 @@ method](/docs/monitor/enable-notifications.md).
 ## What's next?
 
 Learn more about [interacting with charts](/docs/dashboard/interact-charts.mdx) to quickly pan through time, zoom, and
-show/hide dimensions to best understand the state of your node in any timeframe.
+show/hide dimensions to best understand the state of your node in any timeframe. A complete understanding of [chart
+dimensions, contexts, and families](/docs/dashboard/dimensions-contexts-families.mdx) will also help with how Netdata
+organizes its dashboard and operates [alarms](/docs/monitor/configure-alarms.md).
 
 ### Further reading & related information
 
diff --git a/docs/dashboard/interact-charts.mdx b/docs/dashboard/interact-charts.mdx
index d0a447bd43..a7d42e2356 100644
--- a/docs/dashboard/interact-charts.mdx
+++ b/docs/dashboard/interact-charts.mdx
@@ -116,9 +116,10 @@ are, respectively, `Pan Left`, `Reset`, `Pan Right`, `Zoom In`, and `Zoom Out`.
 
 ## What's next?
 
-<!-- We recommend you read up on the differences between [charts, contexts, dimensions, and
-families](/docs/dashboards/chart-dimensions-contexts-families.mdx) to complete your understanding of how Netdata's
-dashboards are organized. -->
+We recommend you read up on the differences between [chart dimensions, contexts, and
+families](/docs/dashboard/dimensions-contexts-families.mdx) to complete your understanding of how Netdata organizes its
+dashboards. Another valuable way to interact with charts is to use the [timeframe
+selector](/docs/dashboard/select-timeframes.mdx), which helps you visualize specific moments of historical metrics.
 
 If you feel comfortable with the [dashboard](/docs/dashboard/how-dashboard-works.mdx) and interacting with charts, we
 recommend moving on to learning about [configuration](/docs/configure/nodes.md). While Netdata doesn't _require_ a
diff --git a/docs/dashboard/select-timeframes.mdx b/docs/dashboard/select-timeframes.mdx
new file mode 100644
index 0000000000..6385ace1eb
--- /dev/null
+++ b/docs/dashboard/select-timeframes.mdx
@@ -0,0 +1,79 @@
+---
+title: "Select timeframes to visualize"
+description: "Netdata's dashboard features a rich timeframe selector, with useful defaults and rich customization, to help you narrow your focus when troubleshooting issues or anomalies."
+type: how-to
+custom_edit_url: https://github.com/netdata/netdata/edit/master/docs/dashboard/select-timeframes.mdx
+---
+
+# Pick timeframes to visualize
+
+While [panning through time and zooming in/out](/docs/dashboard/interact-charts.mdx) from charts is helpful when
+you're looking a recent history, or want to do granular troubleshooting, what if you want to see metrics from 6 hours
+ago? Or 6 days?
+
+Netdata's dashboard features a **timeframe selector** to help you visualize specific timeframes in a few helpful ways.
+By default, it shows a certain number of minutes of historical metrics based on the your browser's viewport to ensure
+it's always showing per-second granularity.
+
+## Open the timeframe selector
+
+To visualize a new timeframe, you need to open the picker, which appears just above the menu, near the top-right cover
+of the dashboard.
+
+![The timeframe selector in the local Agent
+dashboard](https://user-images.githubusercontent.com/1153921/101507784-2c585080-3934-11eb-9d6e-eff30b8553e4.png)
+
+The **Clear** button resets the dashboard back to its default state based on your browser viewport, and **Apply** closes
+the picker and shifts all charts to the selected timeframe.
+
+## Use the Quick Selector
+
+Click any of the following options in the **Quick Selector** to choose a commonly-used timeframe.
+
+- Last 5 minutes
+- Last 15 minutes
+- Last 2 hours
+- Last 6 hours
+- Last 12 hours
+
+Click **Apply** to see metrics from your selected timeframe.
+
+## Choose a specific interval
+
+Beneath the Quick Selector is an input field and dropdown you use in combination to select a specific timeframe of
+minutes, hours, days, or months. Enter a number and choose the appropriate unit of time, then click **Apply**.
+
+## Choose multiple days
+
+Use the calendar to select multiple days. Click on a date to begin the timeframe selection, then an ending date. The
+timeframe begins at noon on the beginning and end dates. Click **Apply** to see your selected multi-day timeframe.
+
+## Caveats and considerations
+
+**Longer timeframes will decrease metrics granularity**. At the default timeframe, based on your browser viewport, each
+"tick" on charts represents one second. If you select a timeframe of 6 hours, each tick represents the _average_ value
+across a larger period of time.
+
+**You can only see metrics as far back in history as your metrics retention policy allows**. Netdata uses an internal
+time-series database (TSDB) to store as many metrics as it can within a specific amount of disk space. The default
+storage is 256 MiB, which should be enough for 1-3 days of historical metrics. If you navigate back to a timeframe
+beyond stored historical metrics, you'll see this message:
+
+![Screenshot of reaching the end of historical metrics
+storage](https://user-images.githubusercontent.com/1153921/114207597-63a23280-9911-11eb-863d-4d2f75b030b4.png)
+
+At any time, [configure the internal TSDB's storage capacity](/docs/store/change-metrics-storage.md) to expand your
+depth of historical metrics.
+
+## What's next?
+
+<!-- We recommend you dive deeper into some additional dashboard features, such as [import/exporting
+snapshots](/docs/dashboards/import-export-snapshots.mdx) or
+[customization](/docs/dashboards/customize-standard-dashboard.mdx). -->
+
+
+
+### Further reading & related information
+
+- [Interact with charts](/docs/dashboards/interact-charts.mdx)
+- [Database engine reference](/database/engine/README.md)
diff --git a/docs/store/change-metrics-storage.md b/docs/store/change-metrics-storage.md
index 46b4dea9cb..2ed026c5c1 100644
--- a/docs/store/change-metrics-storage.md
+++ b/docs/store/change-metrics-storage.md
@@ -60,9 +60,10 @@ method](/docs/configure/start-stop-restart.md) for your system, to change the da
 
 ## What's next?
 
-If you have multiple nodes with the Netdata Agent installed, you can [stream metrics](/docs/store/stream-metrics.md)
-from any number of _child_ nodes to a _parent_ node and store metrics using a centralized time-series database.Streaming
-allows you to centralize your data, run Agents as headless collectors, replicate data, and more.
+If you have multiple nodes with the Netdata Agent installed, you can [stream
+metrics](/docs/metrics-storage-management/how-streaming-works.mdx) from any number of _child_ nodes to a _parent_ node
+and store metrics using a centralized time-series database. Streaming allows you to centralize your data, run Agents as
+headless collectors, replicate data, and more.
 
 Storing metrics with the database engine is completely interoperable with [exporting to other time-series
 databases](/docs/export/external-databases.md). With exporting, you can use the node's resources to surface metrics