Difference between PSObject, Hashtable, and PSCustomObject

Question

Can anybody explain the details? If I create an object using

$var = [PSObject]@{a=1;b=2;c=3}

and then I look for its type using getTy

Answer 1

Say I want to create a folder. If I use a PSObject you can tell it is wrong by looking at it

PS > [PSObject] @{Path='foo'; Type='directory'}

Name                           Value
----                           -----
Path                           foo
Type                           directory

However the PSCustomObject looks correct

PS > [PSCustomObject] @{Path='foo'; Type='directory'}

Path                                    Type
----                                    ----
foo                                     directory

I can then pipe the object

[PSCustomObject] @{Path='foo'; Type='directory'} | New-Item