diff --git a/docs/src/userguide/glossary.rst b/docs/src/userguide/glossary.rst
new file mode 100644
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+.. _glossary:
+
+Glossary
+=============
+
+.. glossary::
+
+ Cartopy
+ A python package for producing maps, and other geospatial data.
+ Allows plotting on these maps, over a range of projections.
+
+ | **Related:** :term:`Matplotlib`
+ | **More information:** `CartoPy Site `_
+ |
+
+ CF Conventions
+ Rules for storing meteorological Climate and Forecast data in
+ :term:`NetCDF Format` files, defining a standard metadata format to
+ describe what the data is.
+ This also forms the data model which iris is based on.
+
+ | **Related:** :term:`NetCDF Format`
+ | **More information:** `CF Conventions `_
+ |
+
+ Coordinate
+ A container for data points, comes in three main flavours.
+
+ - Dimensional Coordinate -
+ A coordinate that describes a single data dimension of a cube.
+ They can only contain numerical values, in a sorted order (ascending
+ or descending).
+ - Auxiliary Coordinate -
+ A coordinate that can map to multiple data dimensions. Can
+ contain any type of data.
+ - Scalar Coordinate -
+ A coordinate that is not mapped to any data dimension, instead
+ representing the cube as a whole.
+
+ | **Related:** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Cube
+ Cubes are the main method of storing data in Iris. A cube can consist of:
+
+ - Array of :term:`Phenomenon` Data (Required)
+ - :term:`Coordinates `
+ - :term:`Standard Name`
+ - :term:`Long Name`
+ - :term:`Unit`
+ - :term:`Cell Methods `
+ - :term:`Coordinate Factories `
+
+ | **Related:** :term:`NumPy`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Cell Method
+ A cell method represents that a cube's data has been derived from
+ a past statistical operation, such as a
+ MEAN or SUM operation.
+
+ | **Related:** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Coordinate Factory
+ A coordinate factory derives coordinates (sometimes referred to as
+ derived coordinates) from the values of existing coordinates.
+ E.g. A hybrid height factory might use "height above sea level"
+ and "height at ground level" coordinate data to calculate a
+ "height above ground level" coordinate.
+
+ | **Related:** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+
+ Dask
+ A data analytics python library. Iris predominantly uses Dask Arrays;
+ a collection of NumPy-esque arrays. The data is operated in batches,
+ so that not all data is in RAM at once.
+
+ | **Related:** :term:`Lazy Data` **|** :term:`NumPy`
+ | **More information:** :doc:`real_and_lazy_data`
+ |
+
+ Fields File (FF) Format
+ A meteorological file format, the output of the Unified Model.
+
+ | **Related:** :term:`GRIB Format`
+ **|** :term:`Post Processing (PP) Format` **|** :term:`NetCDF Format`
+ | **More information:** `Unified Model `_
+ |
+
+ GRIB Format
+ A WMO-standard meteorological file format.
+
+ | **Related:** :term:`Fields File (FF) Format`
+ **|** :term:`Post Processing (PP) Format` **|** :term:`NetCDF Format`
+ | **More information:** `GRIB 1 User Guide `_
+ **|** `GRIB 2 User Guide.pdf `_
+ |
+
+ Lazy Data
+ Data stored in hard drive, and then temporarily loaded into RAM in
+ batches when needed. Allows of less memory usage and faster performance,
+ thanks to parallel processing.
+
+ | **Related:** :term:`Dask` **|** :term:`Real Data`
+ | **More information:** :doc:`real_and_lazy_data`
+ |
+
+ Long Name
+ A name describing a :term:`phenomenon`, not limited to the
+ the same restraints as :term:`standard name`.
+
+ | **Related:** :term:`Standard Name` **|** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Matplotlib
+ A python package for plotting and projecting data in a wide variety
+ of formats.
+
+ | **Related:** :term:`CartoPy` **|** :term:`NumPy`
+ | **More information:** `Matplotlib `_
+ |
+
+ Metadata
+ The information which describes a phenomenon.
+ Within Iris specifically, all information which
+ distinguishes one phenomenon from another,
+ e.g. :term:`units ` or :term:`Cell Methods | `
+
+ | **Related:** :term:`Phenomenon` **|** :term:`Cube`
+ | **More information:** :doc:`../further_topics/metadata`
+ |
+
+ NetCDF Format
+ A flexible file format for storing multi-dimensional array-like data.
+ When Iris loads this format, it also especially recognises and interprets data
+ encoded according to the :term:`CF Conventions`.
+
+ | **Related:** :term:`Fields File (FF) Format`
+ **|** :term:`GRIB Format` **|** :term:`Post Processing (PP) Format`
+ | **More information:** `NetCDF-4 Python Git `_
+ |
+
+ NumPy
+ A mathematical Python library, predominantly based around
+ multi-dimensional arrays.
+
+ | **Related:** :term:`Dask` **|** :term:`Cube`
+ **|** :term:`Xarray`
+ | **More information:** `NumPy.org `_
+ |
+
+ Phenomenon
+ The primary data which is measured, usually within a cube, e.g.
+ air temperature.
+
+ | **Related:** :term:`Metadata`
+ **|** :term:`Standard Name` **|** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Post Processing (PP) Format
+ A meteorological file format, created from a post processed
+ :term:`Fields File (FF) Format`.
+
+ | **Related:** :term:`GRIB Format` **|** :term:`NetCDF Format`
+ | **More information:** `PP Wikipedia Page `_
+ |
+
+ Real Data
+ Data that has been loaded into RAM, as opposed to sitting
+ on the hard drive.
+
+ | **Related:** :term:`Lazy Data` **|** :term:`NumPy`
+ | **More information:** :doc:`real_and_lazy_data`
+ |
+
+ Standard Name
+ A name describing a :term:`phenomenon`, one from a fixed list
+ defined at `CF Standard Names `_.
+
+ | **Related:** :term:`Long Name` **|** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Unit
+ The unit with which the :term:`phenomenon` is measured e.g. m / sec.
+
+ | **Related:** :term:`Cube`
+ | **More information:** :doc:`iris_cubes`
+ |
+
+ Xarray
+ A python library for sophisticated labelled multi-dimensional operations.
+ Has a broader scope than Iris - it is not focused on meteorological data.
+
+ | **Related:** :term:`NumPy`
+ | **More information:** `Xarray Documentation `_
+ |
+
+----
+
+`To top `_
diff --git a/docs/src/userguide/index.rst b/docs/src/userguide/index.rst
index 08923e7662..fdd0c4d03e 100644
--- a/docs/src/userguide/index.rst
+++ b/docs/src/userguide/index.rst
@@ -35,6 +35,7 @@ they may serve as a useful reference for future exploration.
cube_maths
citation
code_maintenance
+ glossary
.. toctree::
diff --git a/docs/src/whatsnew/latest.rst b/docs/src/whatsnew/latest.rst
index 73f7e60351..c1af56b1e5 100644
--- a/docs/src/whatsnew/latest.rst
+++ b/docs/src/whatsnew/latest.rst
@@ -97,6 +97,7 @@ This document explains the changes made to Iris for this release
#. `@ESadek-MO`_, `@TTV-Intrepid`_ and `@trexfeathers`_ added a gallery example for zonal
means plotted parallel to a cartographic plot. (:pull:`4871`)
+#. `@Esadek-MO`_ added a key-terms :doc:`glossary` page into the user guide. (:pull:`4902`)
💼 Internal
| |