Properties require an instance of a type to be created before they can be accessed. Static properties, on the other hand, don't.
A static property is a piece of data; in some cases, this includes constant values, associated with class definitions, that can be retrieved without creating an object instance.
MSDN shows static properties using an S symbol in the leftmost column. For example, the System.Text.Encoding class has a number of static properties denoting different text encoding types, shown in the following screenshot:
PowerShell is also able to list the static properties for a type (or class) using Get-Member with the Static switch:
PS> [System.Text.Encoding] | Get-Member -MemberType Property -Static
TypeName: System.Text.Encoding
Name MemberType Definition
---- ---------- ----------
ASCII Property static System...