What is the difference between the cause and effect of an event in history

The cause of an event is something happened before the event.

The effect of an event is something happened after the event.

You'll have the 'cause' first, then the event will happen.

After the event happened, you will get the 'effects'.

Basically,

cause = why/how the event will happen?

effect = what changes the event brings to us?

Well the cause of a certain event in history will mean something happens.

The effect is the result of the event happening

For example. With 9/11 the cause was the twin towers collapsing. The effect would have been thousands of people dying as the result of the planes being highjacked