H.264, also known as AVC, is a video compression standard used in many broadcasting, recording and streaming workflows. Encoders can produce different profiles, levels and other settings within the standard. A device's broad H.264 compatibility therefore still needs to suit the actual stream's resolution, frame rate and encoding properties to decode it correctly.
A practical example
An older television can handle an ordinary H.264 stream but fail on another stream that exceeds its decoding limits. Examining the actual encoding details is more useful than assuming every file carrying the same codec label places identical demands on the device.
A common misunderstanding
A codec label is not a picture-quality score. A carefully encoded lower-bitrate source can look better than a badly encoded source with a larger advertised number.
Related terms
Further reading
Stable technical definition. Editorial approach