My post How to add a more tag to your post reveals how to break up your posts into smaller sections with a ‘more’ link after them, which automatically goes to the post’s page revealing the full article.
However, there is another way to do this, in the Settings section found on the left sidebar.
Go to the Settings > Reading page:
Within the red circle you will find the option to have your posts presented in full on your blog page, or in a summary format, with the ‘more’ link automatically added.
This is applicable if you want all your posts to look like this. However, if you wish only for selected posts to be abbreviated, then the ‘more tag‘ is the answer.