Well, this is basic programming. That thing does 5 steps. For example:
For each integer A from 1 to 5 do
Create a special effect at center of playable map area
Wait 1 second
This works like this: Step 1: a special effect appears in the middle of the map, step 2 the same, ... same for step 5. So this one creates 5 special effects in the middle of the map each between 1 second interval.