The post excerpt is the summary of an article with the link to access in the post article. It is used to display articles in little space and mostly comes in handy for magazine websites. In this free version, it is only used in one place.
Click on Dashboard> Appearance> Customize> Theme Customization> Post Excerpt
Excerpt length is a filter that limits the words to be displayed within a post summary. It depends on you and the sidebar design of the theme. By default, it is set as 15. You can change the excerpt length number according to your wish.