License Key is unique code which help us to keeps your records with us.
You can find your License Key in your purchase receipt, sent to your email address you have entered while purchase, so enter your correct email address.
License Key is used to activate your purchased copy.
Yes, your purchased product will work without activation.
Well, either you activate your copy or not, its your decision, but if you activate the product then you will get automatic updates for future release of the purchased product. So we recommend you to activate your product using the given License Key.