How wide is a 4E shoe?

I'm curious to know, how wide exactly is a shoe size labeled as 4E? It's often difficult to find accurate measurements for specific shoe widths, especially when it comes to wider sizes like 4E. Is there a standard width measurement that's universally used for 4E shoes, or does it vary depending on the manufacturer? Additionally, how does the width of a 4E shoe compare to narrower sizes like D or B? I'm looking for a clear and concise explanation to help me understand the dimensions of 4E shoes.