Should I use class button inside of an Block or should I create another class elemen__button and new style for It.

[abhinavnepal7]

Just red the title.

[dotnetCarpenter]

it depends. https://en.bem.info/methodology/css/#mixes

Some say that you should create a new block if it does not have any external size, e.i. margin, width, height etc. and then you can optionally add style to it within a block as a block__element.

I would probably style it as part of a bigger block and the first time I copy styles to another block, I can take the overlap CSS and have a base style for a new block, while my two existing blocks can add a few more styles that are different because of the context.