setenv allows sub shells to inherit the value.
Set
set x = "twenty"
echo $x
> twenty
## New Shell
csh
echo $x
x: Undefined variable.
Setenv Note missing '='
setenv x "twenty"
echo $x
> twenty
##New Shell
csh
echo $x
> twenty
setenv allows sub shells to inherit the value.
set x = "twenty"
echo $x
> twenty
## New Shell
csh
echo $x
x: Undefined variable.
setenv x "twenty"
echo $x
> twenty
##New Shell
csh
echo $x
> twenty