What is a Probe Set? What is a Probe pair?

[Pixel08]

Hi I'm a complete beginner with the bioinformatics material - and I was searching around the web and there were these questions listed. I've done a quick google search on them, but couldn't find a really convincing answer on them.

I'm hoping people in this forum could shed some light onto these questions:

What is a Probe Set?
What is a Probe pair?
Why do we need to normalize the microarray data?
The list of genes that you get after an analysis is absolutely unique? Why?
Briefly, how can we assign biological meaning to the list of differentially expressed genes?


Thanks in advance!

[krobison]

Wikipedia is a good place to start when working on homework assignments.