Netbook or Notebook?

I remember a few years back when laptop computers was trendy and dominated at that time where it is set for standard for mobile computing. A few years later and as the technology advances from time to time, there's already a lot of new terms who came in. There are notebooks, netbooks and even ultra-mobile PCs. But what's the difference in it?

I am one of those who are quite confuse about the difference of this mobile pc's.I'm currently using a laptop from e machines. We still call it a laptop since its quite big yet its slim and handy. But based from its product description, it is called a netbook. 

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As I was trying to research about it, I  found out that laptop computers, notebooks and netbooks uses the same basic form factor, but  the main different is  their size. In general, those netbook computers are smaller and lighter than notebook computers, which in turn are smaller and lighter than laptops.

But there are still some laptops that are too large to be considered notebooks or netbooks just like my e machines D732Z.Well, whatever it is, I don't care much as long as it  is reliable and has a good and higher specs. ^_^