what does it mean that it does not CREATE a local variable?

That's mostly true. Consider these three programs:

$var = "value";
print($main::var eq "value" ? "true" : "false", "\n");  # true
[download]

our $var = "value";
print($main::var eq "value" ? "true" : "false", "\n");  # true
[download]

As you can see, with or without our, $var refers to $main::greet. No variable is created. The purpose of our is to do no strict 'vars'; on a per-variable basis. Like no strict 'vars';, the our directive is lexically scoped (although the variable isn't).

Remember that I said "mostly true". The exception is when the scope of the our spans packages.

package Test;
$var = "value";
print($Test::var eq "value" ? "true" : "false", "\n");  # true
[download]

our $var;
package Test;
$var = "value";
print($Test::var eq "value" ? "true" : "false", "\n");  # false
[download]