Polaris Transit

[Jiggy 67]

I understand polar alignement without any problems, but there are a couple of questions, the answers to which I can't find anywhere, someone may be able to answer the following:

• When people refer to the transit of Polaris, what are they talking about??....I know what "transit" means, one body passing across the disc of another, but what is Polaris transiting??
  
• During alignement, software refers to the last time that Polaris transited. How does this aid alignement?? The last time Polaris transited may have been 6pm for example but I am polar aligning at 8pm so how does knowing that it transited at 6pm aid alignement??
  

I'm a visual observer, so I have never polar aligned to the accuracy above, I don't need to at the moment, but one day I hope to get into AP so understanding the above would be usefull.

[Andymac79]

The transit is when its highest in the sky, so lowest in your finder scope. If you use the setting circles on the mount you need to know the time of the last or a particular transit.