Could not find method android() for arguments on root project 'DemoApp'

Hi, apologies if this is in the wrong area.

I am learning to become a Android Developer and I am getting the following error after importing a DemoApp lecture/project.

Error22, 0) Could not find method android() for arguments [build_37t24irnbyoe7akecva1y2tmh$_run_closure3@4e763413] on root project 'DemoApp' of type org.gradle.api.Project.

I am not sure what to do here, or what is causing this. From what I understand it's something to do with the build or project version?

As I understand it, it is something to do with my Gradle Script or the Build Script, but I dont understand what is wrong.

I did some initial research, and found an StackOverFlow article but I can't post the link as I am a new user. But the answer said

You are using the wrong build.gradle file.
In your top-level file you can't define an android block.
Just move this part inside the module/build.gradle file

But I dont understand where you move it to.
Or how I need to fix this.

Can someone please explain what the problem is?
I am using Android Studio 2.2.1