Every blog post should include a meta title and a meta description. Meta titles and meta descriptions are not shown in a blog post, They are hidden behind the scenes, but are still available to represent the post in search engine listings.
The ability to add SEO metadata to a post is usually provided by an SEO plugin. There are many different SEO plugins to choose from.
The SEO plugin I use on my sites and on client sites is the free version of the SEO Framework plugin. The SEO Framework has some premium (paid) extensions which you can add. If your site requires any paid extensions I will contact you about it separately. But for most sites, the free SEO plugin is sufficient.
You would be forgiven for thinking that having to type all this metadata yourself, is a waste of time.
If you prefer not to handcraft each post's SEO metadata, the plugin can do it for you automatically. Given that this portion of search engine optimization can be done automatically, you would be forgiven for thinking that having to create the metadata yourself then type it in, is a waste of time.
It isn't. If you allow any SEO plugin to do the work for you, the values it will choose will be drawn from what you've written in your post. This means the SEO metadata will be duplicates of content that already exists in your post.
Duplicate content should generally be avoided in case it affects your ability to rank in Google. However another reason to avoid it here involves missed opportunity. You would miss an opportunity to add related terms to your page, and to use the SEO metadata as a hook to persuade users to click your links.
Ideally SEO titles and descriptions should be unique, relevant and persuasive. The only way to achieve that is to write them yourself.
Use the SEO Framework plugin's colour coded system to check you have done everything right
Below is an annotated image showing you all the key SEO settings. The numbers refer to those in the diagram below.
Your aim is to have your blog post to show up for relevant search terms and then entice users to click.
When your post is crawled by Google, it should end up in the search results looking something like the diagram below.
Notice where the data you entered shows up.