Permalinks are the permanent url structures to any web site content such as post, page, categories ore even the media types.
Default Permalink
By default Wordpress uses the reference id in its url structure. For example in a default setting a url structure looks like this yoursite.com/?p=123 where 123 refers to the particular id of the page.
Pretty Permalinks
Pretty permalinks are well structured for readability and crafted in a way that makes real sense to the visitor visiting a site.
For example with contrast to default permalink, a pretty permalink will look like:
yoursite.com/about-us/
How are pretty links set up
Wordpress allows various options to setup the permalinks structure. Here is a brief on how we can set up pretty permalinks. Go to Settings > Permalinks via dashboard. Select one of the options that suits you better.
Advantages of using pretty permalinks
Pretty permalinks are standard and readable. Apart from that, it holds significance is Search Engine Optimisation. So this might be another good reason to use pretty permalinks.