Under a magnetic strip the strip for the signature made of paper or by a dusting usually settles down. The signature put on a card serves as a sample with which the seller or the cashier verifies the signature put by the client on a slipa.
The silver card is called business - as the card (Business Card) and is intended not for individuals, and for the staff of the organizations authorized to spend means of the company in these or those cases.
Cards of record happen single (single record / repeated reading) and to repeated rewriting. The memory size of such cards is much more, than at cards with a magnetic strip, the written-down information is protected much better.
Now almost universal distribution was gained by plastic cards, however for identification of the owner the paper (cardboard) cards soldered or pressed in a plastic foil are still used.