Gold credit cards, as with platinum cards, are a type of premium credit card that is offered by credit card companies to their preferred customers. They will also be offered to hand picked individuals that the credit card company would like to add as customers.
In practice gold cards are very similar to platinum cards and there is actually nothing specific meant by the fact that a card is designated a gold card. It is really just a way for each credit card company to differentiate their own products and the various credit cards that they have on offer to their customers. What one credit card company calls a gold card, may be called a platinum credit card by another company, while at the same time, such a card may be given no special designation by another company. The point to remember in all of this is that every credit card has to be looked at and judged on the terms and rates that it offers and if you are going to sign up for any credit card, then you should take the time to consider what it is you are agreeing to and whether or not the offer is attractive to you. You cannot simply rely on the fact that the company offering the card has decided to call it a gold card...