the_excerpt() or the_content()
There are two ways to present a teaser of the content in a post in the WordPress loop.
The first is using “the_content()” command, the normal method used in a single post template to present the whole post. However, it can be used on pages such as the front or index page where only part of the post is required and there is a link to the full post.
This modification is done at the editing stage using the more tool to insert this break mark in the post. This more tag is ignored in the single post template so the full post is shown.
The alternative is to show a portion from the start of the post using “the_excerpt()” command. This has a similar to using the “more” tag in “the_content()” but it is applied to every post when it appears on pages such as the front or index page.
The choice depends on the proficiency of the content authors. Using a fixed excerpt is good so the authors do need to configure the front page teasers.
Conversely, where the content author is more involved in the design and editorial control of the web site, then manually inserting the “more” tag with the_content() is the preferred option. Sometimes the post is short enough to show it all on the front page.