Detailed answer
Use video with controls and a supported source.
A poster offers a preview and preload provides a loading hint. Add captions for spoken material and useful surrounding context. Autoplay is not dependable and may be inappropriate. Verify that both the media and text-track resources load from their deployed URLs.
Example
<video controls preload="metadata" poster="poster.jpg"><source src="lesson.mp4" type="video/mp4"><track kind="captions" src="lesson-en.vtt" srclang="en" label="English"></video>
Understanding the behavior
Native controls provide familiar playback interactions without requiring a custom control implementation. Source format support and server delivery still matter. Provide captions and an understandable surrounding description when the content requires them.
Practical implementation notes
Test playback, pause, volume and keyboard access. Autoplay can be blocked or disruptive and should not be necessary for understanding the page. Include a useful fallback message or link where appropriate.
How to check it
Play the actual file, test native controls, and choose the caption track.
Expected result
Playback controls work and timed captions appear when selected.
Watch out: Fallback text inside video does not replace captions.
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