The idea of a permalink is that every page and every post on your blog has a corresponding, permanent link that can be bookmarked and indexed by search engines, which of course is what you are looking for in terms of your blog or website SEO.
The problem is that sometimes the default permalink may end up looking something like
It is not clear from this permalink what the page or post is about, so it is harder for search engines to index it.
Now compare the above example to the permalink for this post:
So, whenever you are publishing a blog post, do check your permalinks* and ensure that it is clear to readers and search engines what the post is about. It’s a simple SEO tip, but an effective one.
* If using a self-hosted WordPress blog you can change your permalinks under the Settings tab