Why Storage devices have less space then that they promised?

We all purchase pen drive, hard disk, Etc. But do you seen that the storage.But it happened to us. When buy the dealer or company promise to be exact space but after checking it resulted less, usually got angry for the company for false marketing thinking and the shop from where we brought. But they are not responsible for any mistake whether they are company or dealer. But have you ever thought that how do they again and again in huge amount without getting into illegal promise trouble?

The answer is that they are not marketing illegally. I’ll tell you how this confusing have done. A manufacturer or company of producing goods considers 1 Mb to be 1000 kb and we all also thinks that & 1 Gb to be 1000 Mb, 1 Tb to be 1000 Gb. But as per the computer 1mb = 1024kb, 1 GB = 1024Mb, 1Tb=1024 GB .This difference in the method of computation is responsible for this "missing space."

I don’t know why this all happened. But it’s not mistake & not illegal. Let me explain with a example.

Let us take an example of a 16 GB pen drive disk. 

*From a manufacturer’s and company point of view, the 10 GB will have 10*1000*1000*1000 = 16000000000 bytes.

*But from a computer’s point of view, 10GB is actually 10*1024*1024*1024 = 17179869184 bytes.

So, a pen drive that promises to have 16 GB storage space will actually display 14.9012 GB.

So next time be aware for storage device that are purchasing. ;-)