Why is prototyping important step in design process?

[ideaztech]

The prototype gives the customer a complete idea of ​​how the site will look like in the final result. Prototyping allows you to streamline the design development process, focusing on important interface elements

[Little_Bumblebee]

It's cheaper to make a prototype to see if everything works before actually doing all the work.
And it's faster.

Then you get to test it to see where the product needs improvement as well.

[Leavesbound]

Prototyping proves the process.