We back up all default Document libraries and Lists of the Site.

• SharePoint
  • Site Collection  
    • Lists
      • List (with inherited permissions)
        • Items
        • Columns
        • Content Types
        • Views
        • Permissions (link to parent Site Permissions folder)
      • List (with unique permissions)
        • Items
        • Columns
        • Content Types
        • Views
        • Assignments
      • List (with an item that has unique permissions)
        • Items
        • Items permissions
        • Columns
        • Content Types
        • Views
        • Permissions (Link to parent Permissions folder)
          
    • Document Libraries
      • Document Library (with inherited permissions)
        • Content
        • Columns
        • Content Types
        • Views
        • Permissions (Link to parent Permissions folder)
      • Document Library (with unique permissions)
        • Content
        • Columns
        • Content Types
        • Views
        • Assignments
      • Document Library (with an item that has unique permissions)
        • Content
        • Items permissions
        • Columns
        • Content Types
        • Views
        • Permissions (Link to the parent Permissions folder)
      • Site pages
        • Content
          • Modern site page (published pages)
          • Wiki page (published and unpublished pages, unpublished pages restored as published)
          • Web part page (published pages, can only be previewed, not restored)
        • Columns
        • Content Types
        • Views
        • Permissions (Link to parent Permissions folder)
      • Site assets
      • List Template Gallery (this is document library where templates of the List and Document library are saved)
      • Solution Gallery (document library where templates of sites are saved)
    • Site Content Types
    • Site Columns
    • Permissions
      • Groups
      • Assignments
      • Permission Levels
      • Site Administrators
    • Customization
      • Quick launch navigation menu
        Note: We do not backup the quick launch navigation menu for the following site templates: Business Intelligence Center, Enterprise Wiki, Enterprise Search Center, Publishing Portal, Basic Search Center
    • Pages (link to Pages folder)
      Note: This link will be absent for the following Site Templates: Basic Search Center, Blog, Community Portal, Document Center, eDiscovery Center, Project site, Record Center, Visio Process Repository 
    • Term Store
      • Global term sets
      • Local term sets
    • Sub-Sites
      • Sub-Site (with inherited permissions)
        • Lists
        • Document Libraries
        • Site Content Types
          • Link to parent Site Content Type folder
          • List of own Content Types
        • Site Columns
          • Link to parent Site Columns folder
          • List of own Site Columns
        • Permissions (Link to parent Site Permissions folder)
        • Sub-Sites
      • Sub-Site (with unique permissions)
        • Lists
        • Document Libraries
        • Site Content Types
          • Link to parent Site Content Type folder
          • List of own Content Types
        • Site Columns
          • Link to parent Site Columns folder
          • List of own Site Columns
        • Permissions 
          • Assignments (permissions for the site)
          • SharePoint Groups
          • Permission Levels
        • Sub-Sites

Notes:

• We do not back up the quick launch navigation menu for the following site templates: Business Intelligence Center, Enterprise Wiki, Enterprise Search Center, Publishing Portal, Basic Search Center
• The link to Pages folder is absent for the following Site Templates: Basic Search Center, Blog, Community Portal, Document Center, eDiscovery Center, Project site, Record Center, Visio Process Repository 

We do not back up:

• Site collections that are locked. 
• Deleted sites (sites in the Recycle bin)
• Sites with the template type REDIRECTSITE#0 (we back up the original site from where the redirect originates)
• Personal Views of Lists and Document Libraries
• External Lists
• Footer navigation menu
• Top link bar
• Sites themes 
• SharePoint IRM (Information Right Management)
• Project Online (we support the backup of site collections with Web App Part, but do not support the backup of projects)
• SharePoint workflows
• Permissions of SharePoint security groups
• Apps (e.g., AuthTokenProvider)
• Site permissions for groups (only site permissions for users are supported)
• Document Library styles
• Document Library folder column metadata

We do not support the restore of:

• Managed metadata columns (including Term groups)
• Lookup columns
• Calculated columns in lists