Permalinks are the URLs people use to access content on your site. Luckily, WordPress gives you the option to change the permalink structure of your website. This allows for easier sharing, intuitive navigation, and gives your site some added SEO functionality.
WordPress, by default, uses a http://example.com/?p=%ID%
structure. As you are probably aware, this is not very user friendly. Imagine explaining to someone that in order to hear some of your music, they should visit http://example.com/?p=123
.