Most binary options brokers will feature a graph on each asset listed on their platform. In the case of Gold, the graph provided will have a line to indicate the movement of gold prices over time. From the provided graph, you can see how the price of Gold has been changing over time. As such, you can decide on the probable direction that the price will move in the near future. It is on this basis that you make your prediction on whether the price of Gold will rise or fall in the near future.
Some brokers offer all three types, while others offer two, and there are those that offer only one variety. In addition, some brokers also put restrictions on how expiration dates are set. In order to get the best of the different types, traders are advised to shop around for brokers who will give them maximum flexibility in terms of types and expiration times that can be set.

You are taking a risk when trading binary options. If it was a sure fire thing that we would win every time we trade then everyone would be doing it and everyone would be winning. The brokers are there to make money just as you are and on every trade someone always loses. The trick is to minimise the risk of it being you and that any money invested is not going to hurt you if you lose.
Binary options "are based on a simple 'yes' or 'no' proposition: Will an underlying asset be above a certain price at a certain time?"[20] Traders place wagers as to whether that will or will not happen. If a customer believes the price of an underlying asset will be above a certain price at a set time, the trader buys the binary option, but if he or she believes it will be below that price, they sell the option. In the U.S. exchanges, the price of a binary is always under $100.[20]