Azure Tenant vs Azure Subscription

Hi dears,

I always get confused when I ready about Azure Tenant and Azure Subscription.

for me:

1. Tenant without subscription means nothing can be activated in Azure.
2. Having a subscription for me it means I can work in Azure.

So why we create a tenant? what is benefit or relation between subscription and Tenant creation of this link: 

https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/active-directory-access-create-new-tenant

Thanks