Speed is a game concept to indicate how long it takes to complete a given task using a tool.
There are three broad classes of tools in the game, to which speed matters:
As you improve on the quality of the materials, it usually takes less time to complete a task. This is at the cost of more resources to make one of those tools as well as more complexity in terms of the variety of buildings needed.
Crude Basket • Besom Broom • Fishing Rod • Knitting Needles • Shears