Get-Item
Gets the item at the specified location.
Get-Item .\foo
# returns the item foo
Get-ChildItem
Gets the items and child items in one or more specified locations.
Get-ChildItem .\foo
# returns all of the children within foo
note: Get-ChildItem can also recurse into the child directories
Get-ChildItem .\foo -Recurse
# returns all of the children within foo AND the children of the children
