I recently did my first paying WordPress programming job. I still consider myself a novice in this field but tinkering with my own website theme helped me gain enough knowledge so I can be confident enough to advertise I can help my clients with their websites.
While doing some research I came across the_excerpt() function which allows you to call the text in the manual excerpt box. While writing a post you can find this box in the right hand side column and fill it with a short description, a quote or any information that you would like to share about your post. It is possible this box is not visible but you can activate it by going to “More tools and options” in the upper right corner of the post page, go down to “Options” and click on it to open the option window. Check the checkbox next to “Excerpt” under Document panels. It is possible to leave the box empty. WordPress will then automatically use the start of the blog post when calling the function.
The way I like to use it is to make a post archive where I can display a grid of posts boxes. Every box contains the title and the excerpt of the post. In this case the excerpt is a summary of the post itself. Instead of having to search trough an archive with large blocks of text, visitors can now see a quick overview of all the posts available on the site. With some magic from the CSS grid style all the posts will stack neatly on the archive page.