Update glossary (#952)

Adding consumer and distinction between assets and devices.

Fixes #650

Author: cwasicki

docs/user-guide/glossary.md

@@ -61,13 +61,25 @@ components](#component-category) together. It can be connected to the public
 [grid](#grid), or be completely isolated, in which case it is known as an
 island.
 
+Components can be grouped into [assets](#Assets) and [devices](#Devices).
+Assets are core components like generators or storage systems that are crucial from a business perspective,
+whereas devices are the supporting infrastructure essential for the functionality of these assets.
+
 ### Component Category
 
 The category [components](#component) of a [microgrid](#microgrid) belong to.
 
 [Components](#component) of the same category have the same characteristics
 (for example offer the same set of [metrics](#metric)).
 
+Examples of categories are meters, inverters or batteries.
+
+A category can be further divided into types.
+For instance, PV inverters and battery inverters are types under the inverter category.
+
+
+### Assets
+
 #### Battery
 
 A storage system for electrical energy.
@@ -77,14 +89,13 @@ A storage system for electrical energy.
 A generator that produces combined heat and power ([CHP](#chp)). Usually
 powered via combustion of some form of fuel.
 
-#### Converter
-
-Generally refers to [DC-to-DC converter](#dc-to-dc-converter).
-
-#### DC-to-DC Converter
+#### Consumer
 
-An electronic circuit or electromechanical device that converts a source of
-[DC](#dc) from one voltage level to another.
+Typically used in context with a metric, i.e. consumer power or consumer current.
+This aggregates all remaining electrical energy [consumption](#consumption) in a microgrid that are not covered by other asset types and components.
+Under normal circumstances this is expected to correspond to the [gross consumption](#gross-consumption) of the site excluding active parts and battery.
+In [Passive-sign convention](#passive-sign-convention) consumer power is usually positive, but negative values can occur in
+exotic site topologies (e.g. unidentified generators) and or due to sudden short-term effects.
 
 #### EV Charger
 
@@ -99,6 +110,30 @@ A device that converts water into hydrogen and oxygen.
 A point where the local [microgrid](#microgrid) is connected to the public
 electricity grid.
 
+#### PV Array
+
+A collection of [PV](#pv) panels.
+
+#### Solar Panel
+
+A panel with [PV](#pv) cells that generates [DC](#dc) electricity from
+sunlight.
+
+#### Wind Turbine
+
+A device that converts the wind's kinetic energy into electrical energy.
+
+### Devices
+
+#### Converter
+
+Generally refers to [DC-to-DC converter](#dc-to-dc-converter).
+
+#### DC-to-DC Converter
+
+An electronic circuit or electromechanical device that converts a source of
+[DC](#dc) from one voltage level to another.
+
 #### Inverter
 
 A device or circuitry that converts [DC](#dc) electricity to [AC](#ac)
@@ -109,10 +144,6 @@ electricity.
 A device for measuring electrical [metrics](#metrics) (for example current,
 voltage, etc.).
 
-#### PV Array
-
-A collection of [PV](#pv) panels.
-
 #### Pre-charge module
 
 A device that gradually ramp the [DC](#dc) voltage up to prevent any potential
@@ -136,15 +167,6 @@ They are generally placed in front of another [component](#component), e.g., an
 A device for [measuring](#measurement] ambient [metrics](#metric) (for example
 temperature, humidity, etc.).
 
-#### Solar Panel
-
-A panel with [PV](#pv) cells that generates [DC](#dc) electricity from
-sunlight.
-
-#### Wind Turbine
-
-A device that converts the wind's kinetic energy into electrical energy.
-
 ### Component
 
 A device (of a particular [category](#component-category)) within