The default structure of permalinks is www.website.com/2018/05/15/sample-post/. If this structure is used, the date part of the permalink will only be included in URLs for posts – pages will have the URL www.website.com/sample-page/. If a page has the same name as another page, or if a post has the same name as a post published on the same date (with the default permalink structure), a number is added to the end of the name in the URL to distinguish them from each other.
You can change the permalink settings in Settings → Permalinks. The settings page includes a handful of common settings for permalinks, along with a field that allows you to create a custom structure. The permalinks should always include the name of the content. It makes the URLs more readable and descriptive, and it’s also beneficial for your rating in search engines (see Search Engine Optimization).
You can edit the permalink of a specific post or page by going to Posts/Pages → Edit and clicking on a page or post. You then click the “Edit” button next to the permalink directly beneath the title, and a field will appear that allow you to change the permalink of the content. Click the “Ok” button to confirm your changes to the permalink, and then click the blue “Update” button in the “Publish” meta box to save your changes.