Format of WordPress articles

Gallery: This article format is like Image article format, but it allows you to publish a picture gallery.
State: Quickly publish a statement in one of your WordPress post.
Sound: Article format like Video article format, but it is reserved for the publication of an audio type of post.
Discussion: Article format that aims to provide a transcript of a chat conversation type.

An WordPress article format is an optional information that will determine the graphical representation of your post (article) on your site based on the format you have chosen for your post. It is possible to use it only if your WordPress theme supports these option.

This option enable the theme developers not to reinvent the wheel when, for example, want to display articles based on videos. In addition, it creates a commonality between all the themes.

The article formats are debates within the community of developers of the WordPress core, because in time the list of article formats changes, so the article formats are not unanimously accepted.

For the version 4.2 of WordPress and the theme I use, the article formats are: Standard, Aside, Image, Video, Quote, and Link.

Standard: This is the default format. This simply means that here, the author of the post can put what everything he wants as content, from the standard blog post, to video, a gallery of images, sound, or short notes.
Aside : This post format allows an author to publish a short note, which would aim to provide additional information, or just make a short note alone.
Image : This format is used to highlight an image.
Video Article format to insert a video into the post. It is not the only format to support video, but it can be used for all kind of videos, including embedded code from YouTube, for ex., or video hosted on your site in a native way (since WordPress 3.6)
Quote : Article format that allows you to publish a quote.
Link: Article format designed primarily to allow you to quickly share a link with your visitors.