See the following for AEM Sites 6.4 enhancements in detail:
Site Administration
New Content Tree rail to quickly navigate a site hierarchy. In combination with the list view, this restores the Classic UI interaction model to browse a site.
Improved scrolling in card and list view of large folders.
Improved interaction with the search results - the back button restores the prior search result.
Additional keyboard shortcuts, for most common actions, such as to open a particular rail, to edit, move and delete pages, or to open properties.
Ability to disable keyboard shortcuts (enable/disable in Preferences).
Stop showing time stamps across all UI relative after 7 days (set default in Preferences).
Page Editor
Updated device list for responsive site preview, now including Apple iPhone 8, 8 Plus and X, and Samsung S7
Moved default location for template design information away from /etc/design to support sites specific settings in /conf. Customers that upgrade from prior AEM releases can remain using /etc/design.
AEM includes version 1.12.4 of the jQuery library to provide maximum compatibility with existing custom code. Modifications have been done by Adobe to address known security issues.
Content Fragments & Editor
Introduced Structured Content Models as foundation for content fragments
Model editor UI
Pre-configured data elements for content fragment models (single-line text, multi-line text, number, boolean, date&time, enumeration, content reference, tags)
Improved the usability of the AEM Content Fragment editor
Added enhanced output options for AEM Content Fragments
New Content Fragment component, as part of Core Components. See code on GitHub.
Content Services support with JSON output via Sling Model Exporter
Experience Fragments
Introduced Experience Fragment Building Blocks, to facilitate re-using content between Experience Fragments variations by grouping components and by allowing easy reference within variations.
Added the ability to add Experience Fragments to translation projects via the reference rail
Added the ability to start workflows with Experience Fragments via the timeline rail
Reference rail now shows where an Experience Fragment is being used in AEM
Configuration of template locations now allows authors to define on a global or folder level what Experience Fragment templates are allowed to use
Faceted search now supports advanced filtering, such as published/non-published, exported to social media and Adobe Target
Added single social media login when exporting Experience Fragments to Pinterest or Facebook
Integrated AEM Experience Fragments with Adobe Target. Synchronizing Experience Fragments to Target will create offers in Adobe Target that can be used with Target’s Visual Experience Composer to embed it in any Target enabled experience.
Translation
Enhanced the usability of AEM Translation projects:
Support for multiple target languages in one project
Option to automatically promote and delete translation launches
Option to schedule recurring execution of translation projects (daily, weekly, monthly, yearly)
Enhanced translation project tiles with more detailed status information
Introduced Reverse Translation Memory Update, to update translation memory in 3rd-party translation management system after local content edits in AEM
Translation workflows now support grouped language roots
Added ability to assign arbitrary names to language roots, and use JCR property for mapping to ISO code
Smart translation updates now recognize new pages that were added to a language master branch
Introduced translation status reporting in Sites Admin list view
Multi-Site Management (MSM)
Improved MSM scalability by using an Oak-based index vs in-memory (LiveCopyIndex)
Launches
Improved performance of launches that contain large site tree and if there are many Launches active
Improved auto-promotion and publish of launches with multiple root pages.
Fixed an issue that prevented the responsive device preview to work with pages edited in context of a launch.
Content Targeting & Simulation
Support folders to organize segments based on site/context (CQ-94620)
Moved default location for segments into /conf to have site/context specific Segment lists.
AEM & Adobe Target
Integrated AEM Experience Fragments with Adobe Target. Synchronizing Experience Fragments to Target will create offers in Adobe Target that can be used with Target’s Visual Experience Composer to embed it in any Target enabled experience.
Adobe Target mbox.js version 63 now included. Adobe recommends to switch implementation to at.js.
at.js version 1.2.2 now included. Adobe recommends to use either Dynamic Tag Management (DTM) or Adobe Experience Platform Launch to provision at.js into the site.
AEM & Adobe Analytics
s_code.js H.27.5 now included. Adobe recommends to switch implementation to AppMeasurement.js
AppMeasurement.js 1.8.0 now included. Adobe recommends to use either Dynamic Tag Management (DTM) or Adobe Experience Platform Launch to provision AppMeasurement.js into the site.
Added support for Screens Players to be connecting to AEM publish servers for command & control and channel downloads (instead of directly to AEM author).
Added ability to group channel assignments in Schedules
Channel assignments now have start and end date
Device Dashboard now shows player shell and firmware version
Device Dashboard list shows connection status of player
Added Google Chrome OS support for AEM Screens Player