I am planning to keep breadcrumb in my project.
Which one is a good approach: Keeping in vertical or in horizontal form? What are the pros and cons?
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This realy depends on your application. Most breadcrumbs on Websites are in horizontal form because that's a nice middle ground from functionallity, completeness and screen space used.
But that doesn't mean it fits your product. What are you trying to achieve? What type of Software is it? You realy have to give us more information in order to get a helpful answer.
I would argue the more common method would be to go with a horizontal breadcrumb, as this quite easy to see a step by step progression and journey the user has taken to navigate to where they are.
However there are instances where vertical breadcrumbs are advantageous but it does really depend on what it is you are working on.