Bandwidth
The maximum rate at which data can move across a connection.
Business connections are usually sold on download speed, but upload is what carries cloud backups, video calls, and file sharing, and asymmetric consumer-grade connections run out of it first.
Contention and service level also matter. A cheaper connection shared among many subscribers behaves differently under load than a dedicated one with a guaranteed rate.
Where this comes up
Bandwidth sits inside our networks and infrastructure work. If you are trying to work out what this means for your own environment rather than in the abstract, that is the page worth reading next, and a short call will get you a straight answer faster than either.
Related terms
Latency The delay between sending data and it arriving, usually measured as a round trip in milliseconds. Quality of service Prioritizing certain network traffic so that latency-sensitive applications stay usable under load. Service level agreement A contractual commitment to defined levels of availability or response, usually with a remedy when they are missed. Uptime The proportion of time a system is available, usually expressed as a percentage over a period.