Set boolean set it between true or false one time. Toggle bolean change every time that the event happen.
An example of SET BOOLEAN is: the playerbox have a boolean called run, if i press "x" button, the boolean will be true and it belong true. You need another condition to change that. (you drive this)
the same example with toggle boolean: every time that you press "X" the boolean will change. if the boolean was in true, this will turn to false. Same to false. Every time that you press "x", the boolean will change.
Sorry for my english but isn't my native language