Mbps stands for megabits per second — millions of bits per second — and is the everyday unit for measuring video bitrate at HD and 4K scales. It's a measure of data rate (over time), not file size. Note the small "b" for "bit": Mbps and MB/s are not the same. A 10 Mbps stream is delivering about 1.25 MB per second, because there are 8 bits in a byte. This conversion trips up everyone at first.
Reference points worth memorising. A 1080p H.264 streaming rendition sits around 4–8 Mbps. A 1080p HEVC rendition for the same quality is around 2.5–4 Mbps. A 4K HDR HEVC stream runs 15–25 Mbps. AV1 at 4K HDR is around 10–18 Mbps for the same quality. Video calls (Zoom, Teams, WebRTC) typically use 1–3 Mbps. For network capacity: 4G delivers 5–20 Mbps in real-world conditions, home Wi-Fi varies wildly from 20 to 500+ Mbps, fibre starts at 100 Mbps.
For a streaming product, Mbps is the daily vocabulary of capacity planning. Adaptive bitrate ladders are designed in Mbps rungs spaced so each viewer's network can comfortably select one — typical rungs at 1, 2, 4, 8, 15 Mbps for a 1080p ladder. CDN cost is directly proportional: a stream at 4 Mbps for 90 minutes consumes 2.7 GB of egress per viewer; that times millions of viewers per month is the line-item that pays for the engineering. Codec migration economics are easiest to communicate in Mbps: "moving from HEVC to AV1 cuts our 4K average rendition from 18 Mbps to 13 Mbps — that's 28 % off our 4K CDN bill at the same quality".
