General Meaning:
* Headline: Used for the title of a news article or other piece of writing.
* Title: Used for the name of a book, movie, song, etc.
* Legend: Used to explain symbols or images in a diagram or map.
* Subtitle: A secondary title that appears below the main title.
* Description: A detailed account of something.
* Label: A short piece of text that identifies something.
For Images:
* Overline: Text placed above an image.
* Cutline: Text placed below an image, especially in a newspaper.
* Callout: Text that highlights a specific part of an image.
* Annotation: A note or comment added to an image.
For Videos:
* Subtitle: Text displayed on the screen to translate or provide additional information.
* Voiceover: Spoken narration that accompanies a video.
The best word to use will depend on the specific context.