NetLogo - What is 1 distance unit in NetLogo?

I am working on traffic simulations using NetLogo for a post graduate project.

For turtles to move forward we can specify the number of units it can move e.g. fd 1, which would mean the turtle moves for开发者_如何学编程ward by 1. What is this 1 unit? Is it equal to 1 patch or equal to the size of the turtle?

Each step is the same size as the patches.

As Luis said, each step is the size of one patch, but remember that steps are not restricted to integers, eg. fd 0.7 is a valid command and will move a turtle forward seven tenths of the size of a patch.

The patches represent a roadway (if you're discussing a traffic simulation model) and one scales patches in a model appropriately, e.g. 1 patch=25 m....etc.!