What is the use of skill in wed and sed?
any explanation?thx

Let's say you have an action that says
if(my.skill1==1) do_something;
if(my.skill1==2) do_a_different_thing;

In WED, when you assign the action to that entity, you can set the skills and that way help tell the function what to do. It's a way to kinda change and make functions more flexible on-the-go.

You can set for example player's health in SED, so you'll be able to change it in WED, from skills.