Blog post publishing

Sorry I could’ve worded my question better.

You know how when you go to some blogs (like this one: Flexport Blog | Freight Forwarding & Customs Brokerage Insights) they preview their blog posts (but not the full length)

How do you do that? And then how do you make it link/click to display the full blog post by itself?

Is it just adding a ‘read more/view’ text or button that goes to that page?