Test Automation Framework for different types of products

I have read some basic definition of what Test Automation Framework is but I wish to know in easy words and more practical example.

Lets say.

I own a company that makes different kinds of products made on different platforms for different purposes. E.g. Spotify Web Version, Google Map apps on ipad /Android and Ebay.com on several platforms.

Now since all these products are of different nature and prurpose on different platform. How do we implement a test Automation framework that covers all these.

PS: Aim of question is to understand what is actually meant by framework in test automation and how can it be implemented for products worlds apart?