Sillybean

Excerpts

An excerpt is, as the box says, a summary of your post. Some themes show excerpts rather than the full content when posts are listed, either on the home page or in archives. If a theme calls for an excerpt and none is specified, it will be generated automatically from the post content. However, any HTML formatting will be removed. If your content contains lists or tables, the results might be very odd. You can preserve HTML formatting in excerpts using the Advanced Excerpt or the_excerpt Reloaded plugin.

Excerpts are shown with a continuation string. By default, ‘[...]’ is appended to your excerpt text. As of version 2.9, this can be modified via plugins.

Also new in 2.9 is the option to modify the length of your excerpts. By default, they are 55 words long.