If you had your choice would you want a link to a page on your site to have the following format:
- https://longest.com/?p=1, OR
The latter if you would like to increase your pages relevancy in search engines such as Google.
Instead of just a variable as a number your link will be more relevant using the keywords from your post title. In WordPress you navigate to the Options menu, then choose Permalinks and pick the format you would like. See the screen shot below for the setup.
Permalinks are permanent links, meaning the URL to that page will not change. These links will receive a higher search engine ranking with the title of the post in the URL. This is an excellent way to receive higher search engine rankings and therefore natural search traffic without paying for the clicks.