The “attachment details” fields let you add information to media uploaded to the Media Library. This information lets you find things again, and, depending on where and how the media is used, will show up on the siite.
There are four fields to fill in
- Alternative text – is what a screen reader user will hear when they are listening, as opposed to looking at, a page. It is the text alternative to the image.
- Title – the title field is used internally by WordPress for media search. It’s also a media title for attachment pages, galleries. There are other features that might use it. It used to show up on hover
- Caption – the text that shows up under the image
- Description – the description usually won’t show up on the screen or get read by the screen reader. Sometimes this information is visible/audible. For example, a gallery on a site with the JetPack plugin installed will show the description. There may be other spots, so check!