What is the widest shoe size?

Excuse me, could you please clarify something for me? I'm curious about the concept of "the widest shoe size." Is there a universally accepted standard for what constitutes the widest shoe size? Does it vary based on the manufacturer or the style of the shoe? And if so, how does one determine which size is the widest among the various options available? I'm looking for a concise and straightforward answer to this question, as I'm trying to get a better understanding of shoe sizing in general. Thank you in advance for your help.