simple question

I am a complete novice on this topic. Assuming that one requires a sim card to attach to a device like: Huawei, is it possible to transfer my sim card from my mobile phone and connect my mobile phone, laptop etc to it through wifi ? If not why not ?

You mean a MiFi device?

Yes, you can put your phone SIM in one and it will work. You need to check any usage is within your terms and conditions or you might end up with a bill. You won't be able to make calls or send texts though. (except for non cellular network services such as Skype).

If you mean a USB modem then you could plug it into a PC and set up internet connection sharing through it, or there are routers which take a USB 3G dongle.

Really? Never seen htat with Vodafone contrat SIMs at least and sounds somewhat draconian!