dns from a client logon perspective

[alpha88]

I would like to know how dns works in respect to active directory sites and services
Everytime I see an example on dns they always show internet resolution someone typing in

http://www.microsoft.com

for example. I want to see dns from a client logon side for example what happens when someone logs onto there workstation. How are sites and logon servers selected I’ve never seen anyone lay this process out its always that same internet resolution example.