void cannot be instantiated and is used for the cast operator
null has one instance only (namely: $null)
object from which all other types, except null are derived, either directly or indirectly. bool
char
int
long
float (single is a synonym for float)
double
decimal
switch which is used for parameters.
string
array
hash table
xml
regex
ref
scriptblock
math (used for constants e, pi and functions like abs(), max(), sin() etc.)
ordered (which is considered a pseudo type)
pscustomobject (which is ony used for conversions) getType(): $foo = 42 $foo.getType()
-is operator checks if a value is of a given type. -as operator casts a value into a different type. class keyword.