First of all, what are Permalinks in Blogger.com?
Permalinks are the name and URL of your blog posts on Blogger.com. Normally when you write a blog post on Blogger.com, it's automatically generated for you based on the title of your blog post. The main reason you want to customise it is to help make your blog posts more readable to your visitors so that they know exactly what your website page is about.
The other reason would be for SEO (search engine optimisation) benefit, which supports your visitors need to be able to read your website easily.
