The idea behind them is creating a variable for your target (usually called "target") and then setting up two aliases. The first alias "defines" the variable or changes it. IE tar "istirith" would change the variable to istirith.
<br>
<br>The second alias is always the same and sends "kill 'target'", with 'target' being your variable, which of course depends on whatever you set it to. In this case, it will send "kill istirith"
<br>
<br>Confusing? Yes. But it's usually easy to set up depending on your client, and very very easy to use.