oEmbed, as described at oEmbed.com, is a specification that allows media providers like Flickr, YouTube and others to provide data for consumer applications like WordPress about media. So by including an Embed (Use the File uploader and choose “From URL” and paste the link to the page that contains the media, not the media file itself) in a post or page, WordPress can retrieve the relevant specs on the media file and formulate a properly formatted embed accordingly.
You know, I probably couldn’t care less about oEmbed. So I can embed media from different providers, great. Sarcasm intended.
The thing is, I don’t work with media that much. Sure, I’ll stick in the odd YouTube video here or there, and I’ll also use pics once in a while to illustrate a point, but in those cases the standard tools just don’t cut it.
For example, I’ll Press something from a cool YouTube video, and while WordPress will automatically fetch the embed code for me, it’s usually miniscule and doesn’t represent the content I want. By using the custom embed options available to every embeddable video on YouTube, I get to customise things like the border, related content, and size – you’ll have noticed that videos seen on this website will have a grey border, show no related content after the video finishes playing, and, most importantly, are bigger than the normal YouTube size.
From what I understand about oEmbed, it won’t let me customise these options at all – “…and formulate a properly formatted embed accordingly.”
I’d say more about customisability and WordPress, but that’s for another time.