My (variable) versus Our (variable)! Please explain the necessity for use....

[jason corbett]

Hello folks. I am very thankful for all the help that I am getting here. The only 
thing is when I get some suggestions, I don't normally get the "whys" along with it. 
One in particular is use of "my" to assign variables, versus using "our". Until I can 
get a Perl scripting class to take, I am teaching myself and sometimes these books 
don't delve into the simple things. So who can answer this?
 
Thanks,
JC