How to enable TAX for all products?

Hi, i want to add the german TAX to all my products. Is there a way to set all products or root categories with the TAX?

I have many Categories with products, like this:

Example Category 1
Example Category 2
..


I created a TAX Class "Example Category 1" (same like categories ??

Then under TAX Providers -> Tax By Country & State  -> new TAX RATE Germany

Could i define a TAX Rate for the whole shop (products) ??

As you have already created a class "TAX" which will be common for all the products,

Products category has nothing to do with tax,

what you can do is, whenever you're adding any product(s), define it's tax category as ="TAX", that's all you have to do, if you are importing number of products, then define tax category = "TAX" for all the products.

and Go to admin section >   Configuration   >   Tax   >   Tax Providers  

Choose 4th option that says' Fixed Rate" , click on Edit

Choose 2nd Tab : Configuration

Enter the tax rate what you want should be charged while checkout.

and save the settings, and you're good to go.