How does Bitcoin work?

How does Bitcoin work? Imagine that there is a room with surveillance cameras watching every small and large and recorded for life, and in this room five transparent shops so that the coins can be seen inside clearly, and each of the proceeds of the five owned by someone standing outside the room with a code to open the proceeds, and this The person wants to buy something, so he goes to the dealer and gives the trader the code of the proceeds, then the dealer enters the room and his face is covered so that he can not be seen and take the money and put it in his possession in the same room and come out, so these cameras have recorded that it was The transfer of a sum of money, but do not know the proceeds of gold or money to or from lost in Thing.