There are multiple ways to do so. 

ArcGIS system of record can provide data in open standard – I3S specification which is OGC community standard. It can be elevation, it can be BIM, it can be 3D features, it can be lidar data, you name it. And this standard is scalable, 3D Estonia is example of this. And this standard is supported by a significant number of GIS market players.

This can be product interoperability, and soon you will see a demo, how Autodesk products can read 2.5 or 3D data from ArcGIS for design project, and ArcGIS is being able to read it in a native form and integrate it into system of record as 3D features, or 2.5D features. Another example of product interoperability is ArcGIS for AR/VR, where ArcGIS is integrated into Unity or Unreal engines. 

Direct read of data – ArcGIS can read different BIM standards like Revit, native reading of IFC is coming in ArcGIS Pro 2.8. Infrastructure BIM standards like Autodesk Civil3D is already available. Support of common data environment – BIM360 is available, and ArcGIS GeoBIM which is coming later this year. 

Finally – ArcGIS Data interoperability can translate data from one format or service to another. 

Yes, you can embeds maps almost to any application. It can be a web page, it can be a desktop app, in can be mobile app. Esri support variety of technologies and API's to do this. Esri’s ArcGIS Platform brings market-leading location services to you as a platform as a service (PaaS). You can integrate location into your apps and business systems with the most comprehensive and high-quality set of location services, data, and mapping tools available. Build with the mapping libraries of your choice or use Esri’s full range of mapping libraries and no-code options that reduce time to market and promote creative design. ArcGIS Platform offers an affordable and flexible location-focused PaaS for software developers, businesses, and organizations that need to bring location innovation into their products, solutions, and systems. You can find more info at:
https://www.esri.com/en-us/arcgis/products/arcgis-platform/overview 
https://developers.arcgis.com/documentation/

As the Map viewer Beta is available for ArcGIS Enterprise starting from 10.8.1 as an optional install. You can use dictionary symbology - Military symbology. You can work with the symbology in ArcGIS Online as the Map Viewer is in general availability since ArcGIS Online April 2021 update.

The given data examples have been used for demonstrating software capacity only and do not relate to the operational setup of property tax calculation in Lithuania.

The tools and techniques used in the demo:

Empirical Bayesian Kriging

Ordinary Least Squares (OLS)

Optimized Hot Spot Analysis

Mean Center

Directional Distribution

Points To Track Segments

Find Meeting Locations

Find Cotravelers

Classify Movement Events

The data used in the presentation is not public and was intentionally prepared for this demo.  The supposed users of the presented techniques are organizations conducting investigative analysis. As an option you may use ArcGIS Tracker to collect data where your field personnel have been to gain greater understanding on movement patterns.

ArcGIS Field Maps now replaces the functionality of ArcGIS Collector, ArcGIS Explorer, and ArcGIS Tracker. These products (Collector, Explorer, Tracker) are currently available to download and are fully supported. However, they will be retired in December 2021.  For more information read: https://www.esri.com/arcgis-blog/products/collector/field-mobility/deprecation-notice-for-selected-field-apps/

The tools and techniques used in the demo:

Empirical Bayesian Kriging

Ordinary Least Squares (OLS)

Optimized Hot Spot Analysis

Mean Center

Directional Distribution

Points To Track Segments

Find Meeting Locations

Find Cotravelers

Classify Movement Events

Yes, UtilityNetwork has topology dataset stored in GeoDatabase, and it is exposed as a web service. This DataSet is a technology change and supercedes old GeometricNetwork. When published as a service, UtilityNetwork has separate service end-points for management versioning, long transaction editing, topology, diagram operations.

Tools and techniques presented in ArcGIS Pro demo:

Layer blending - Multiply

Eyedropper

Arcade - custom code

Legend. Fitting strategy - Manual columns

Custom arcpy script to export web map with reports

Add 3D Formats to Multipatch

Inference - Create and reshape

Make route

Calibrate route

Matrix heat chart

Make aggregation query layer (2.8)

Exploratory 3D analysis - elevation profile

As this tools produces a query layer, it could be published on Enterprise. So Yes, the query layers are actually SQL queries that act as layers in map.

According current plans ArcGIS Pro 2.8 should be available in May. Please monitor Esri communication (https://www.esri.com/arcgis-blog/overview/) or subscribe to our newsletters for being timelly informed.

Yes, the query layers are actually SQL queries that act as layers in a map. It is similar to views - the layer is sql query result. Initial testing shows that processing time is significantly faster than using GP tool to create aggregated layer. Existing tool's execution time grows linearly to record count, the new layer aggregated query layer's refresh time should stay almost the same.

For data access and usage please contact local utility company.

For data access and usage please contact local utility company.

Arcade is an expression language and it is available not only in ArcGIS Dashboards where it was demonstrated during the technical presentations. You can use it in ArcGIS Pro as well. Here is a resource that will help You to get familiar with the syntax and use of such expressions: https://developers.arcgis.com/arcade/  Technical demonstration included an expression that changed the colour of an indicator in ArcGIS Dasboards based on a value. Here is the example: "var color = IIF($datapoint.count >= 1, '#FF0000','white');"

ArcGIS Hub contains  similar functionality as ArcGIS Enterprise sites. ArcGIS Hub has additional capabilities (for example Community engagement part) and it is cloud based SAAS solution. ArcGIS Enterprise Sites comes with ArcGIS Enterprise on your own IT infrastructure.

There is no single definition what is a digital twin. There are different datasets representation ways with different level of details.

ESO (www.eso.lt) 

Go to https://www.esri.com/en-us/arcgis/products/arcgis-utility-network/overview. You will find many predefined UtilityNetwork DB models, sample data, publishing and editing ArcGIS Pro maps. Just choose your preffered industry: Electric, Gas, Water, Telecommunications. For single use, ArcGIS Pro standard is required. For multiuser editing, you will need ArcGIS Enterprise license.

Here is a list of web sites that will get you started:

• Initial steps and examples when using deep learning packages from ArcGIS Living Atlas: https://www.esri.com/arcgis-blog/products/arcgis-pro/imagery/deep-learning-with-arcgis-pro-tips-tricks/
• ArcGIS Deep Learning webinars and articles: https://landing-geoai.hub.arcgis.com/
• Video demos of different deep learning workflows: https://demos-geoai.hub.arcgis.com/
• Articles about how deep learning is implemented in ArcGIS: https://developers.arcgis.com/python/guide/geospatial-deep-learning/
• Sample notebooks for various deep learning workflows with sample data: https://developers.arcgis.com/python/sample-notebooks/

Deep learning analysis on point cloud is currently available only through Python Notebooks. Here is a sample Notebook that contains code for running pre-trained point cloud classification model (like the one from ArcGIS Living Atlas): 
https://github.com/Esri/arcgis-python-api/blob/conference_talks/ready_to_use_model_guides/using_deep_learning_package_of_tree_point_classification_model_in_arcgis_api_for_python.ipynb

You can also find more information on how to setup an environment for point cloud classification here:
https://developers.arcgis.com/python/guide/point-cloud-segmentation-using-pointcnn/

With ArcGIS Pro 2.8, there will be geoprocessing tools available for preparing, training and classifying point clouds using deep learning. You will be able to use these tools with ArcGIS Pro Basic license with 3D Analyst extension. 

For other deep learning workflows, that include imagery, you will need Image Analyst extension with any ArcGIS Pro license level. In case of interactive object detection (Exploratory analysis), ArcGIS Pro Advanced or ArcGIS Pro with Image Analyst extension is required.

ArcGIS Velocity differs from ArcGIS GeoEvent Server and ArcGIS GeoAnalytics Server in many ways, including product capabilities and business model. On a high level, GeoEvent Server and GeoAnalytics Server are on-premises software, while Velocity is a software-as-a-service (SaaS). More info at: https://www.esri.com/arcgis-blog/products/ext-server-geoevent/real-time/real-time-qa-from-the-2020-esri-user-conference/.