They are not the same thing.
Unfortunately, too many industry people conflate them.
Worse, resolution and compression can silently undermine each other.
Compare the two images below. The resolution (aka pixel count) is exactly the same but the compression levels (and bandwidth) are much different:
Because of the compression difference, even though everything else is the same, the visual quality is much different.
Resolution vs Compression
Resolution, in surveillance, means the number of pixels (1MP, 2MP, 5MP, etc.) See: IPVM's Resolution Tutorial
Compression, in surveillance, means how much the pixels / video is compressed. There is a scale from minimum to maximum. In H.264, it is called quantization, ranging from 0 (least) to 51 (most). See: IPVM's Video Quality / Compression Tutorial.
All IP cameras compress video, typically in the middle of that scale. IPVM testing shows 28 is average though manufacturers vary somewhat. Moreover, manufacturers generally do not reveal the actual quantization level, displaying their own scale. To learn more, see: IP Camera Manufacturer Compression Comparison
Making Lower Resolution Look Like Higher Resolution
In this test, we took a series of 720p IP cameras, decreased the compression levels to see how far we had to go to make it 'look' like a 1080p camera with default compression levels. We then compared bandwidth consumption of each camera.
Making Higher Resolution Looks Like Lower Resolution
Also, in this test, we took a series of 5MP and 1080p cameras, increased their compression levels to see how far we had to go to make it 'look' like lower resolution cameras (1080p / 720p respectively) with default compression levels.
Our goal is to understand and show you:
- How much compression can impact visual quality?
- What benefits are there to reducing compression levels?
- What benefits are there to increasing compression levels?
- Can you get better quality or bandwidth consumption from such changes?