Bufferbloat is a phenomenon whereby excess buffering of packets of data inside a network (the thing that carries to the internet into your home or place of work) causes high latency and jitter, as well as reducing the overall network throughput.
Latency or a delay in data packets arriving particularly adversely affects voice over IP (like Skype calls) and video streaming (including video conferencing). It means that broadband connections seem a lot slower than they should be.
Jim Gettys is one of the leading experts on bufferbloat, researching this at Bell Labs, the research and development arm of Alcatel Lucent.
Why should you care? Well this potentially impacts cloud and real-time content or communications services making them much less useful than one would have thought.