Study this example situation:
Sarah is in her car. She is on her way to work.
She is driving to work.
This means: she is driving now, at the time of speaking.
The action is not finished.
Am/is/are+ -ing is the present continuous:
I am (=I’m) | driving
he/she/it is (=he’s etc.) | working
we/you/they are (=we’re etc.) | doing etc.