What exactly is a Blogspot subdomain and how is it assigned?

A Blogspot subdomain refers to the default web address provided to a blog created on Google's Blogger platform. It follows the format `yourblogname.blogspot.com`. When you create a new blog on Blogger, you're prompted to choose a unique address, and this chosen address automatically becomes the prefix to `.blogspot.com`, forming your blog's initial URL. This serves as its primary online identity until a custom domain is optionally configured.