oEmbed

oEmbed is a format for allowing an embedded representation of a URL on third party sites. The simple API allows a website to display embedded content (such as photos or videos) when a user posts a link to that resource, without having to parse the resource directly. (You can read more about the spec here.)

Buttondown leverages oEmbed in two ways:

1. We're a valid and registered provider of oEmbed content. This means that if you paste a Buttondown link into a service that supports oEmbed, it should automatically expand into a preview of the content — whether that's a subscribe form or an archive of your newsletters.
2. We detect and parse oEmbed links in your newsletters. If you paste a link to a YouTube video, for example, we'll automatically expand that into a preview of the video.

If all of this sounds like gibberish, don't worry! It's a pretty technical concept that you don't need to worry about unless you're building a service that needs to support oEmbed links. If you're a traditional author, everything should "just work" without you needing to worry about it.