Difference between Advertising vs Promotion

What is the difference between Advertising vs Promotion? I was asking my self.
So the answer what i come for me is gos like this:

Advertising:
Its when You talk to Audeins thru Communication Channels.
You can say whatever you want - like we are an open a new shop, we have new collection, we looking for new staff for Our team, etc.

Promotion:
This is something different from our regular activities.

Examples
Regular price is 10$ but for the next 2 weeks is 5$.
Buy 1 get 1 free
Free bites

And then you can advertise thru channel (TV, Radio, Magazine online) that we have this month promotion of 1+1)