kbps and Mbps are the standard units of bitrate: kilobits per second (thousands) and megabits per second (millions) respectively. They measure data rate, not file size — note the small "b" for bit, which is one-eighth of a byte. So 8 Mbps of video bandwidth corresponds to about 1 MB of file per second. This small distinction trips up everyone the first time and is a common source of confusion in technical conversations.
Concrete benchmarks worth memorising. Audio: speech codecs use 8–32 kbps, music streaming runs 128–320 kbps. Video: a 1080p H.264 stream sits around 4,000–8,000 kbps (4–8 Mbps); 4K HDR HEVC around 15,000–25,000 kbps (15–25 Mbps); the same 4K HDR in AV1 about 10,000–18,000 kbps. Networks: 4G mobile delivers 5–20 Mbps comfortably, home Wi-Fi 50–500 Mbps, fibre 100+ Mbps to 10 Gbps. The pattern: video bitrates are designed to fit comfortably inside common network bitrates with headroom for variability.
For a product team, kbps/Mbps are the everyday vocabulary of streaming. Two practical reminders. First, adaptive bitrate ladders are configured in kbps/Mbps per rung — knowing the typical mobile-connection capacity tells you which rungs viewers will actually receive. Second, CDN cost is billed by bytes delivered, so cutting bitrate by 30 % through a better codec (say HEVC to AV1) directly cuts the bandwidth bill by 30 % at the same quality. The conversion is straightforward: a stream at 4 Mbps for 90 minutes uses about 2.7 GB of CDN egress per viewer.
