Permalinks

Permalinks are the permanent URLs of your blog posts or pages on your website. Permalinks are a huge deal when creating content or you want to promote your website out on the web world. When people link to your content or share your content or when Google indexes your pages, they all use permalinks. That is why you would want to shoe pretty permalinks, not long and messy gibberish type of permalinks. By default, WordPress comes with a permalink prototype

http://www.YOURSITE.com/?p=123

You will need to make adjustments to your website's permalinks as soon as you create your website. Because this type of structure gives you no room for optimization neither for humans or search engines. You can create a custom URL structure for your permalinks and archives. To customize your permalink, go to WP Dashboard > Settings > Permalinks

Common Settings

Plain - This is the default permalinks that WordPress sets for each website, it is combined with letters, numbers, and symbols, it can create quite some chaos. The 123 number is the ID of a given post or page in the database.
Day and Name - This permalink will use the day the blog post/page was published and the name of the blog post/page.
Month and Name - Would create the same permalink as the one above only this time the month and the year of the published blog post/article and its name.
Numeric - This type of permalink will show the numerical order in which the blog post/page is archived in the database.
Post Name - This option would create no fuzz, it only uses the name of your blog post/page and generates it as a permalink.
Custom Structure - Here you can specify the desired structure of your permalink, you can choose to add %postname%, %post_id%, %year%, %category%, and many more.

The best structure to go for with permalinks would be the Post Name type of structure since it generates a short and memorable URL that can be very useful in SEO. Once you have chosen your preferred structure, click on Save Changes to make sure your settings are saved in the database. For more information on how to use permalinks, you can follow up with this WordPress article.