Add glossary page. Add some glossary definitions and references

Author: badlop

content/admin/configuration/database.md

@@ -72,6 +72,10 @@ with the [`default_db`](toplevel.md#default_db) top-level option:
 
 <!-- md:version updated in [24.06](../../archive/24.06/index.md) -->
 
+def:update
+: Modify the database schema and all its tables to match the installed ejabberd version.
+  Not to be confused with [upgrade ejabberd](def:upgrade) or [switch schema](def:switch).
+
 The [update_sql_schema](toplevel.md#update_sql_schema) top-level option
 allows ejabberd to create and update the tables automatically in the SQL database
 when using MySQL, PostgreSQL or SQLite.
@@ -140,8 +144,12 @@ remember to use the proper SQL schema!
 For example, if you are using MySQL and choose the _default_ schema, use `mysql.sql`.
 If you are using PostgreSQL and need the _new_ schema, use `pg.new.sql`.
 
+def:switch
+: Change the database schema and all its tables from `default` schema to `new` schema.
+  Not to be confused with [upgrade ejabberd](def:upgrade) or [update schema](def:update).
+
 If you already have a MySQL or PostgreSQL database with the _default_ schema and contents,
-you can upgrade it to the _new_ schema:
+you can switch it to the _new_ schema:
 
 * *MySQL*:
 Edit the file `sql/mysql.old-to.new.sql` which is included with ejabberd,

content/admin/configuration/listen.md

@@ -37,6 +37,10 @@ listen:
 
 ## ejabberd_c2s
 
+def:c2s
+: Client to Server connection in XMPP.
+  Opposed to [](def:s2s).
+
 Handles c2s connections.
 
 General listen options supported:
@@ -59,6 +63,10 @@ General listen options supported:
 
 ## ejabberd_s2s_in
 
+def:s2s
+: Server to Server connection in XMPP.
+  Opposed to [](def:c2s).
+
 Handles incoming s2s connections.
 
 General listen options supported:

content/admin/guide/clustering.md

@@ -75,6 +75,10 @@ need to take into account:
 
 ## Clustering Setup
 
+def:erlang node
+: A node in erlang connected to a cluster.
+  See [Erlang node name](security.md#erlang-node-name)
+
 ## Adding a node to a cluster
 
 Suppose you have already configured ejabberd on one node named

content/admin/guide/security.md

@@ -24,14 +24,17 @@ Most of them are TCP ports, except the explicitely mentioned ones:
 
 ## epmd
 
+def:epmd
+: Small name server included in Erlang/OTP and used by Erlang
+  programs when establishing distributed Erlang communications.
+  See [`epmd (Erlang Port Mapper Daemon)`](https://www.erlang.org/doc/apps/erts/epmd_cmd.html)
+
 !!! tip
     If you setup `ERL_DIST_PORT` in `ejabberdctl.cfg` to a port number
     (for example `5210`) then Erlang will listen only in that port,
     instead of starting the `epmd` program and listen in 4269 + ramdom port.
 
-[`epmd (Erlang Port Mapper Daemon)`](https://www.erlang.org/doc/apps/erts/epmd_cmd.html)
-is a small name server included in Erlang/OTP and used by Erlang
-programs when establishing distributed Erlang communications. ejabberd
+ejabberd
 needs `epmd` to use `ejabberdctl` and also when clustering ejabberd
 nodes. This small program is automatically started by Erlang, and is
 never stopped. If ejabberd is stopped, and there aren't any other
@@ -74,7 +77,11 @@ erl ... -kernel inet_dist_use_interface "{127,0,0,1}"
 
 ## Erlang Cookie
 
-The Erlang cookie is a string with numbers and letters. An Erlang node
+def:cookie
+: Random alphanumeric string assigned to each erlang [](def:node) used to secure connections between erlang nodes.
+  See [Security in distributed erlang](https://www.erlang.org/doc/system/distributed#security).
+
+An Erlang node
 reads the cookie at startup from the command-line parameter
 `-setcookie`. If not indicated, the cookie is read from the file
 `$HOME/.erlang.cookie`.
@@ -110,7 +117,7 @@ different programs in the same machine.
 Setting a secret cookie is a simple method to difficult unauthorized
 access to your Erlang node. However, the cookie system is not ultimately
 effective to prevent unauthorized access or intrusion to an Erlang node.
-The communication between Erlang nodes are not encrypted, so the cookie
+The communication between Erlang nodes are not encrypted, so the [](def:cookie)
 could be read sniffing the traffic on the network. The recommended way
 to secure the Erlang node is to block the port 4369.
 
@@ -125,7 +132,7 @@ Using the option `-sname` instead of `-name` is a simple method to
 difficult unauthorized access to your Erlang node. However, it is not
 ultimately effective to prevent access to the Erlang node, because it
 may be possible to fake the fact that you are on another network using a
-modified version of Erlang `epmd`. The recommended way to secure the
+modified version of Erlang [](def:epmd). The recommended way to secure the
 Erlang node is to block the port 4369.
 
 ## Securing Sensitive Files

content/admin/install/next-steps.md

@@ -50,6 +50,16 @@ regarding `epmd` consult the section relating to
 
 ## Administration Account
 
+def:admin account
+: Account registered in ejabberd with administrative privileges granted in the ejabberd configuration file.
+  Features that take into consideration those privileges:
+  [api_permissions](../configuration/toplevel.md#api_permissions),
+  [ejabberd_web_admin](../guide/managing.md#web-admin),
+  [mod_announce](../configuration/modules.md#mod_announce),
+  [mod_configure](../configuration/modules.md#mod_configure),
+  [mod_http_api](../configuration/modules.md#mod_http_api),
+  [mod_muc](../configuration/modules.md#mod_muc), ...
+
 Some ejabberd installation methods ask you details for the first account, and take care to register that account and grant it administrative rights;
 in that case you can skip this section.
 

content/admin/upgrade/index.md

@@ -1,5 +1,14 @@
 # Upgrade Procedure for ejabberd
 
+def:upgrade
+: Install a version of the program newer than the currently installed one.
+  Not to be confused with [update](def:update) or [switch schema](def:switch).
+
+def:update
+: Modify your program installation to match the requirements of the new program version.
+  This usually involves updating your configuration, your database schema, your API client, your custom modules...
+  Not to be confused with [upgrade ejabberd](def:upgrade) or [switch schema](def:switch).
+
 This document contains administration procedure for each version upgrade.
 Only upgrade from version N to N+1 is documented and supported.
 If you upgrade from an older version than previous one, you have to review all
@@ -79,7 +88,7 @@ or any other tasks. If the fix you plan to apply requires a module restart,
 you can use this alternative:
 [restart_module](../../developer/ejabberd-api/admin-api.md#restart_module).
 
-## Note on database schema upgrade
+## Note on database schema update
 
 ejabberd automatically updates the Mnesia table definitions at startup when needed.
 If you also use an external [database](../configuration/database.md) (like MySQL, ...)

content/developer/ejabberd-api/index.md

@@ -17,13 +17,17 @@ how to start using ejabberd's API,
 how to adjust it to your needs,
 and integrate ejabberd with your existing systems.
 
-## API Backends
+def:API command
+: Command defined in some ejabberd module API backend, that can be executed using some API frontend.
 
-ejabberd's API currently includes over 200 commands,
+ejabberd's API currently includes over 200 API Commands,
 see [API Reference](admin-api.md) for a detailed list of all the existing commands.
 Alternatively you can view the list of commands grouped by their [API Tags](admin-api.md).
 
-Those commands are defined and implemented in Erlang or Elixir modules.
+## API Backends
+
+API commands are defined and implemented in Erlang or Elixir modules
+that can be considered "API backends".
 Some modules included in ejabberd define their commands,
 while the majority of the existing commands are defined and implemented in:
 
@@ -36,7 +40,9 @@ see [Commands](commands.md) page for details.
 
 ## API Frontends
 
-The API commands are exposed through interfaces. Available interfaces are:
+The API commands are exposed through interfaces,
+implemented in modules that can be considered "API frontends".
+Available interfaces are:
 
 - [ejabberdctl](../../admin/guide/managing.md#ejabberdctl) command-line tool
 - [mod_http_api](../../admin/configuration/modules.md#mod_http_api) for HTTP ReST calls using JSON data

content/glossary.md

@@ -0,0 +1,19 @@
+# Glossary
+
+<glossary::def>
+
+---
+
+def:command
+: May refer to:
+
+    - [](def:ad-hoc command)
+    - [](def:API command)
+    - shell command
+
+def:node
+: May refer to:
+
+    - disco node, see [mod_disco](admin/configuration/modules.md#mod_disco)
+    - [](def:erlang node)
+    - pubsub node, see [mod_pubsub](admin/configuration/modules.md#mod_pubsub)