fluent: docs: updating key concepts for style

concepts/key-concepts.md

@@ -1,25 +1,28 @@
 ---
-description: >-
-  There are a few key concepts that are really important to understand how
-  Fluent Bit operates.
+description: Learn these key concepts to understand how Fluent Bit operates.
 ---
 
-# Key Concepts
+# Key concepts
 
-Before diving into [Fluent Bit](https://fluentbit.io) it’s good to get acquainted with some of the key concepts of the service. This document provides a gentle introduction to those concepts and common [Fluent Bit](https://fluentbit.io) terminology. We’ve provided a list below of all the terms we’ll cover, but we recommend reading this document from start to finish to gain a more general understanding of our log and stream processor.
+Before diving into [Fluent Bit](https://fluentbit.io) you might want to get acquainted
+with some of the key concepts of the service. This document provides an
+introduction to those concepts and common [Fluent Bit](https://fluentbit.io)
+terminology. Reading this document will help you gain a more general understanding of the
+log and stream processor.
 
-* Event or Record
-* Filtering
-* Tag
-* Timestamp
-* Match
-* Structured Message
+- Event or Record
+- Filtering
+- Tag
+- Timestamp
+- Match
+- Structured Message
 
 ## Event or Record
 
-Every incoming piece of data that belongs to a log or a metric that is retrieved by Fluent Bit is considered an Event or a Record.
+Every incoming piece of data that belongs to a log or a metric that's retrieved by
+Fluent Bit is considered an _Event_ or a _Record_.
 
-As an example consider the following content of a Syslog file:
+As an example, consider the following content of a Syslog file:
 
 ```text
 Jan 18 12:52:16 flb systemd[2222]: Starting GNOME Terminal Server
@@ -28,30 +31,31 @@ Jan 18 12:52:16 flb systemd[2222]: Started GNOME Terminal Server.
 Jan 18 12:52:16 flb gsd-media-keys[2640]: # watch_fast: "/org/gnome/terminal/legacy/" (establishing: 0, active: 0)
 ```
 
-It contains four lines and all of them represents **four** independent Events.
+It contains four lines, representing four independent Events.
 
-Internally an Event is comprised of:
+Internally, an Event is comprised of:
 
-* timestamp
-* key/value metadata (since v2.1.0)
-* payload
+- timestamp
+- key/value metadata (v2.1.0 and greater)
+- payload
 
 ### Event format
 
 The Fluent Bit wire protocol represents an Event as a 2-element array
 with a nested array as the first element:
 
-```javascript
+```javascript copy
 [[TIMESTAMP, METADATA], MESSAGE]
 ```
 
 where
 
-* TIMESTAMP is a timestamp in seconds as an integer or floating point value (not a string);
-* METADATA is a possibly-empty object containing event metadata; and
-* MESSAGE is an object containing the event body.
+- _`TIMESTAMP`_ is a timestamp in seconds as an integer or floating point value
+  (not a string).
+- _`METADATA`_ is a possibly empty object containing event metadata.
+- _`MESSAGE`_ is an object containing the event body.
 
-Fluent Bit versions prior to v2.1.0 instead used:
+Fluent Bit versions prior to v2.1.0 used:
 
 ```javascript
 [TIMESTAMP, MESSAGE]
@@ -62,74 +66,79 @@ streams.
 
 ## Filtering
 
-In some cases it is required to perform modifications on the Events content, the process to alter, enrich or drop Events is called Filtering.
+You might need to perform modifications on the Event's content. The process to alter,
+append to, or drop Events is called [_filtering_](data-pipeline/filter.md).
 
-There are many use cases when Filtering is required like:
+Use filtering to:
 
-* Append specific information to the Event like an IP address or metadata.
-* Select a specific piece of the Event content.
-* Drop Events that matches certain pattern.
+- Append specific information to the Event like an IP address or metadata.
+- Select a specific piece of the Event content.
+- Drop Events that match a certain pattern.
 
 ## Tag
 
-Every Event that gets into Fluent Bit gets assigned a Tag. This tag is an internal string that is used in a later stage by the Router to decide which Filter or Output phase it must go through.
+Every Event ingested by Fluent Bit is assigned a Tag. This tag is an internal string
+used in a later stage by the Router to decide which Filter or
+[Output](data-pipeline/output.md) phase it must go through.
 
-Most of the tags are assigned manually in the configuration. If a tag is not specified, Fluent Bit will assign the name of the Input plugin instance from where that Event was generated from.
+Most tags are assigned manually in the configuration. If a tag isn't specified,
+Fluent Bit assigns the name of the [Input](data-pipeline/input.md) plugin
+instance where that Event was generated from.
 
 {% hint style="info" %}
-The only input plugin that **does NOT** assign tags is [Forward](../pipeline/inputs/forward.md) input. This plugin speaks the Fluentd wire protocol called Forward where every Event already comes with a Tag associated. Fluent Bit will always use the incoming Tag set by the client.
+The [Forward](../pipeline/inputs/forward.md) input plugin doesn't assign tags. This
+plugin speaks the Fluentd wire protocol called Forward where every Event already
+comes with a Tag associated. Fluent Bit will always use the incoming Tag set by the
+client.
 {% endhint %}
 
-A Tagged record must always have a Matching rule. To learn more about Tags and Matches check the [Routing](data-pipeline/router.md) section.
+A tagged record must always have a Matching rule. To learn more about Tags and
+Matches, see [Routing](data-pipeline/router.md).
 
 ## Timestamp
 
-The Timestamp represents the _time_ when an Event was created. Every Event contains a Timestamp associated. The Timestamp is a numeric fractional integer in the format:
+The timestamp represents the time an Event was created. Every Event contains a
+timestamp associated. A timestamp always exists, and is set by the Input plugin or
+discovered through a data parsing process.
+
+The timestamp is a numeric fractional integer in the format:
 
 ```javascript
 SECONDS.NANOSECONDS
 ```
 
-### Seconds
-
-It is the number of seconds that have elapsed since the _Unix epoch._
-
-### Nanoseconds
+where:
 
-Fractional second or one thousand-millionth of a second.
-
-{% hint style="info" %}
-A timestamp always exists, either set by the Input plugin or discovered through a data parsing process.
-{% endhint %}
+- `_Seconds_` is the number of seconds that have elapsed since the Unix epoch.
+- `_Nanoseconds_` is a fractional second or one thousand-millionth of a second.
 
 ## Match
 
-Fluent Bit allows to deliver your collected and processed Events to one or multiple destinations, this is done through a routing phase. A Match represent a simple rule to select Events where it Tags matches a defined rule.
+Fluent Bit lets you deliver your collected and processed Events to one or multiple
+destinations through a routing phase. A _Match_ represents a rule to select Events
+where a Tag matches a defined rule.
 
-To learn more about Tags and Matches check the [Routing](data-pipeline/router.md) section.
+To learn more about Tags and Matches, see [Routing](data-pipeline/router.md).
 
-## Structured Messages
+## Structured messages
 
-Source events can have or not have a structure. A structure defines a set of _keys_ and _values_ inside the Event message. As an example consider the following two messages:
+Source events can have a structure. A structure defines a set of `keys` and `values`
+inside the Event message to implement faster operations on data modifications.
+Fluent Bit handles every Event message as a structured message.
 
-### No structured message
+Consider the following two messages:
 
-```javascript
-"Project Fluent Bit created on 1398289291"
-```
-
-### Structured Message
+- No structured message
 
-```javascript
-{"project": "Fluent Bit", "created": 1398289291}
-```
+  ```javascript
+  "Project Fluent Bit created on 1398289291"
+  ```
 
-At a low level both are just an array of bytes, but the Structured message defines _keys_ and _values_, having a structure helps to implement faster operations on data modifications.
+- With a structured message
 
-{% hint style="info" %}
-Fluent Bit **always** handles every Event message as a structured message.
-For performance reasons, we use a binary serialization data format called [MessagePack](https://msgpack.org/).
-
-Consider [MessagePack](https://msgpack.org/) as a binary version of JSON on steroids.
-{% endhint %}
+  ```javascript
+  {"project": "Fluent Bit", "created": 1398289291}
+  ```
 
+For performance reasons, Fluent Bit uses a binary serialization data format called
+[MessagePack](https://msgpack.org/).