Usage of "virtual interface" and "virtual"

UVM
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3

In reply to dave_59:

Sorry my typo,

What is the difference usage between
type1.

virtual interface sys_if_vif vif;

and
type2.

virtual sys_if_vif vif;

I came across some examples such as type1 or type2.

I’m confused it. So I checked it from

But they are working as the same.