What is the difference between C:\Users\Default and C:\Users\Default User folders?

What is the difference between C:\Users\Default and C:\Users\Default User folders?

PS $ & "$HOME/psh/dirsize.ps1" "C:\Users\Default"  2.01 MiBPS $ & "$HOME/psh/dirsize.ps1" "C:\Users\Default User"  dir : Access to the path "C:\Users\Default User" is denied.  At C:\Users\t2-sma\psh\dirsize.ps1:2 char:21+"{0:n2} MiB" -f ( ( dir $dirName -force -recurse | measure -property  ...+                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ CategoryInfo          : PermissionDenied: (C:\Users\Default User:String) [Get-ChildItem], UnauthorizedAccessException+ FullyQualifiedErrorId : DirUnauthorizedAccessError,Microsoft.PowerShell.Commands.GetChildItemCommand  0.00 MiB

• Both C:\Users\Default and C:\Users\Default User exists :

  PS $ dir "C:\Users" -Force | ? Name -like 'Default*'  Directory: C:\Users    Mode          LastWriteTime  Length  Name    ----          -------------  ------  ----    d-rh--   31/05/2023   10:58          Default    d--hsl   07/12/2019   10:30          Default User

  
  
• dir says C:\Users\Default User is a junction, but surprisingly PowerShell says nothing:

  $ dir /a "C:\Users" | findstr Default  31/05/2023  09:58    <DIR>          Default  07/12/2019  10:30    <JUNCTION>     Default User [C:\Users\Default]PS $ (gi "C:\Users\Default User\" -Force).LinkType