ASP.net assembly loading from GAC or Bin

For quite a while I have been going back and forth reading msdn documentations to figure out how does an assembly gets loaded at runtime. When an assembly is in the bin of your application and also in the GAC, what gets loaded at runtime, GAC or bin? This post is a quick reference guide so that I come back to it and get the short answer rather than parse through the msdn documentation each time.