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<a href="#"><span></span>Ditto Protocol</a>
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<li><a href="protocol-overview.html">Overview</a></li>
<li><a href="protocol-twinlive.html">Twin/live channel</a></li>
<li><a href="protocol-specification.html">Specification</a></li>
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<a href="#"><span></span>→ commands/events</a>
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<li><a href="protocol-specification-things-create-or-modify.html">Create/Modify</a></li>
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<li><a href="protocol-specification-things-delete.html">Delete</a></li>
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<a href="#"><span></span>→ commands/events</a>
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<li><a href="protocol-specification-policies-delete.html">Delete</a></li>
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<a href="#"><span></span>→ Things examples</a>
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<li><a href="protocol-examples-creatething.html">Create a Thing</a></li>
<li><a href="protocol-examples-deletething.html">Delete a Thing</a></li>
<li><a href="protocol-examples-modifything.html">Modify a Thing</a></li>
<li><a href="protocol-examples-retrievething.html">Retrieve a Thing</a></li>
<li><a href="protocol-examples-retrievethings.html">Retrieve multiple Things</a></li>
<li><a href="protocol-examples-modifypolicyid.html">Modify the Policy ID of a Thing</a></li>
<li><a href="protocol-examples-createattributes.html">Create Attributes</a></li>
<li><a href="protocol-examples-deleteattributes.html">Delete Attributes</a></li>
<li><a href="protocol-examples-modifyattributes.html">Modify Attributes</a></li>
<li><a href="protocol-examples-retrieveattributes.html">Retrieve Attributes</a></li>
<li><a href="protocol-examples-createattribute.html">Create a single Attribute</a></li>
<li><a href="protocol-examples-deleteattribute.html">Delete a single Attribute</a></li>
<li><a href="protocol-examples-modifyattribute.html">Modify a single Attribute</a></li>
<li><a href="protocol-examples-retrieveattribute.html">Retrieve a single Attribute</a></li>
<li><a href="protocol-examples-createthingdefinition.html">Create a Definition</a></li>
<li><a href="protocol-examples-deletethingdefinition.html">Delete a Definition</a></li>
<li><a href="protocol-examples-modifythingdefinition.html">Modify a Definition</a></li>
<li><a href="protocol-examples-retrievethingdefinition.html">Retrieve a Definition</a></li>
<li><a href="protocol-examples-createfeatures.html">Create Features</a></li>
<li><a href="protocol-examples-deletefeatures.html">Delete Features</a></li>
<li><a href="protocol-examples-modifyfeatures.html">Modify Features</a></li>
<li><a href="protocol-examples-retrievefeatures.html">Retrieve Features</a></li>
<li><a href="protocol-examples-createfeature.html">Create a single Feature</a></li>
<li><a href="protocol-examples-deletefeature.html">Delete a single Feature</a></li>
<li><a href="protocol-examples-modifyfeature.html">Modify a single Feature</a></li>
<li><a href="protocol-examples-retrievefeature.html">Retrieve a single Feature</a></li>
<li><a href="protocol-examples-createdefinition.html">Create Feature Definition</a></li>
<li><a href="protocol-examples-deletedefinition.html">Delete Feature Definition</a></li>
<li><a href="protocol-examples-modifydefinition.html">Modify Feature Definition</a></li>
<li><a href="protocol-examples-retrievedefinition.html">Retrieve Feature Definition</a></li>
<li><a href="protocol-examples-createproperties.html">Create Feature Properties</a></li>
<li><a href="protocol-examples-deleteproperties.html">Delete Feature Properties</a></li>
<li><a href="protocol-examples-modifyproperties.html">Modify Feature Properties</a></li>
<li><a href="protocol-examples-retrieveproperties.html">Retrieve Feature Properties</a></li>
<li><a href="protocol-examples-createproperty.html">Create a single Property</a></li>
<li><a href="protocol-examples-deleteproperty.html">Delete a single Property</a></li>
<li><a href="protocol-examples-modifyproperty.html">Modify a single Property</a></li>
<li><a href="protocol-examples-retrieveproperty.html">Retrieve a single Property</a></li>
<li><a href="protocol-examples-createdesiredproperties.html">Create desired Feature Properties</a></li>
<li><a href="protocol-examples-deletedesiredproperties.html">Delete desired Feature Properties</a></li>
<li><a href="protocol-examples-modifydesiredproperties.html">Modify desired Feature Properties</a></li>
<li><a href="protocol-examples-retrievedesiredproperties.html">Retrieve desired Feature Properties</a></li>
<li><a href="protocol-examples-createdesiredproperty.html">Create a single desired Property</a></li>
<li><a href="protocol-examples-deletedesiredproperty.html">Delete a single desired Property</a></li>
<li><a href="protocol-examples-modifydesiredproperty.html">Modify a single desired Property</a></li>
<li><a href="protocol-examples-retrievedesiredproperty.html">Retrieve a single desired Property</a></li>
<li><a href="protocol-examples-errorresponses.html">Error responses</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>→ Things merge examples</a>
<ul>
<li><a href="protocol-examples-mergething.html">Merge a Thing</a></li>
<li><a href="protocol-examples-mergepolicyid.html">Merge the Policy ID of a Thing</a></li>
<li><a href="protocol-examples-mergeattributes.html">Merge Attributes</a></li>
<li><a href="protocol-examples-mergeattribute.html">Merge a single Attribute</a></li>
<li><a href="protocol-examples-mergethingdefinition.html">Merge a Definition</a></li>
<li><a href="protocol-examples-mergefeatures.html">Merge Features</a></li>
<li><a href="protocol-examples-mergefeature.html">Merge a single Feature</a></li>
<li><a href="protocol-examples-mergefeaturedefinition.html">Merge Feature Definition</a></li>
<li><a href="protocol-examples-mergeproperties.html">Merge Feature Properties</a></li>
<li><a href="protocol-examples-mergeproperty.html">Merge a single Property</a></li>
<li><a href="protocol-examples-mergedesiredproperties.html">Merge desired Feature Properties</a></li>
<li><a href="protocol-examples-mergedesiredproperty.html">Merge a single desired Property</a></li>
<li><a href="protocol-examples-errorresponses.html">Error responses</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>→ Policies examples</a>
<ul>
<li><a href="protocol-examples-policies-createpolicy.html">Create a Policy</a></li>
<li><a href="protocol-examples-policies-deletepolicy.html">Delete a Policy</a></li>
<li><a href="protocol-examples-policies-modifypolicy.html">Modify a Policy</a></li>
<li><a href="protocol-examples-policies-retrievepolicy.html">Retrieve a Policy</a></li>
<li><a href="protocol-examples-policies-modifypolicyentries.html">Modify entries</a></li>
<li><a href="protocol-examples-policies-retrievepolicyentries.html">Retrieve entries</a></li>
<li><a href="protocol-examples-policies-createpolicyentry.html">Create a single entry</a></li>
<li><a href="protocol-examples-policies-deletepolicyentry.html">Delete a single entry</a></li>
<li><a href="protocol-examples-policies-modifypolicyentry.html">Modify a single entry</a></li>
<li><a href="protocol-examples-policies-retrievepolicyentry.html">Retrieve a single entry</a></li>
<li><a href="protocol-examples-policies-modifysubjects.html">Modify subjects</a></li>
<li><a href="protocol-examples-policies-retrievesubjects.html">Retrieve subjects</a></li>
<li><a href="protocol-examples-policies-createsubject.html">Create a single subject</a></li>
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<h1 class="post-title-main">Glossary</h1>
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<div class="post-content">
<h2 id="common-terms">Common terms</h2>
<dl>
<dt>IoT</dt>
<dd>Internet of Things</dd>
<dt>IIoT</dt>
<dd>Industrial Internet of Things - also known as ‘Industry 4.0’</dd>
<dt>CQRS</dt>
<dd>Command-Query Responsibility Segregation. A pattern Ditto applies in order to handle commands (ModifyCommands in Ditto) and queries (QueryCommands in Ditto) differently, e.g. by reading queries from memory and persisting commands to a datastore.</dd>
<dt>RQL</dt>
<dd>Resource Query Language</dd>
<dt>SSE</dt>
<dd>Server Sent Events - one way messaging/push from a HTTP server to a consuming client (e.g. a browser).</dd>
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<h2 id="ditto-specific-terms">Ditto specific terms</h2>
<dl>
<dt>Asset</dt>
<dd>An asset can be anything from a tangible and physical device to the more intangible such as the reputation of a company. In our context we define an asset as any item, entity, application or even system of applications that can be registered at Eclipse Ditto using the <code class="highlighter-rouge">Thing</code> concept.</dd>
<dt>Thing</dt>
<dd>A Thing is a generic entity and is mostly used to cluster multiple Features and manage the access to the data and functionality the Thing represents. A Thing may have additional meta data (Attributes) that describes the Thing in more detail.</dd>
<dt>ACL</dt>
<dd>An access control list (ACL) holds the current status on who (subject) is permitted to which extent (read, write, administrate) to manage a Thing.</dd>
<dt>Policy</dt>
<dd>A Policy enables developers to configure fine-grained access control in an easy way. A specific policy defines who (subject) is granted or revoked permissions (rights) on a specific resource. The resource can be defined as rough or as fine-grained as necessary for the respective use case.</dd>
<dt>Attributes</dt>
<dd>Attributes describe the Thing in more detail and can be of any type. Attributes can be used to find Things. Attributes are typically used to model rather static properties at the Thing level. Static means that the values do not change as frequently as property values of Features.</dd>
<dt>Feature</dt>
<dd>A Feature clusters a set of coherent Properties and has an optional Feature definition.</dd>
<dt>Feature properties and desiredProperties</dt>
<dd>A feature may consist of a distinct set of properties, which are functional or logically coherent. The feature properties can represent: <em>properties</em> (e.g. values as reported by a physical device) or <em>desiredProperties</em> (e.g. values set via a remote management UI, aiming to trigger the device integration layer to change the device configuration). Each property itself can be either a simple scalar value or a complex object. Allowed is any JSON object.</dd>
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