What is video or audio bitrate?

Question

Video

There is a video file with a video bitrate of 2644 kb/s and an audio bitrate of 448 kb/s. But what is bitrate? Wikipedia says: the number of bits used to transfer / process data per unit of time. Is it more understandable? A video file is represented on a hard disk by a sequence of many bits. What is the role of bitrate? The number of bits that the processor processes per second and sends to the image or sound output device?

Answer 1

Video or audio clips are usually compressed with some kind of codec . Codecs are different, with different settings, and can produce different picture or sound quality.
For example, here is the same video clip, about 10 minutes long, compressed with different codecs:
https://peach.blender.org/download/
Consider two cases:
320×180 - 62 MB
640×360 - 115 MB
Both have approximately 600 seconds, it turns out that the first has an average bitrate of 108352 bps, and the second has 200977 bps.
Often, modern codecs produce a file with a variable bitrate. Scenes where there are a lot of changes get a higher bitrate, while relatively static scenes get a lower bitrate. Although sometimes there are those where the bitrate does not change throughout the entire video.

What is the role of bitrate? The number of bits that the processor processes per second and sends to the image or sound output device?

Suppose the processor can process more. Bitrate is not a characteristic of the processor, but a property of that record or stream (from YouTube, for example).