Data Transfers · Downloads and large files
Why does a large download show “pieces” and several streams in its progress?
Short answer: Large downloads come down in pieces (so they can resume), several at once (so they're faster). Progress shows pieces arrived and each active stream's speed, which helps tell a slow server from a stuck piece.
A large download is fetched in pieces so it can resume after an interruption, and several pieces come down at once to make it faster. The detail pane shows how many pieces have arrived out of the total, and a small panel with each stream currently downloading a piece and its speed.
It helps you tell "the server is slow" (all streams slow) from "one piece is stuck" (one stream stalled). The file count still reads one file, because it is one file.
Related: Streams per file · Large downloads that resume