Gold biscuits are much more convenient to buy and sell then traditional gold bars, as they are much thinner and flatter, and as a result are a very popular gold bar to invest in.
The primary difference between a gold biscuit and a traditional gold bar is in the manufacturing process. Gold biscuits are manufactured by a mint or gold refinery in a similar manner to coins in that they are stamped out of a sheet of gold, rather than being cast like an ingot.
Gold biscuit manufacturers include Johnson and Matthey, Credit Suisse and the Perth Mint, amongst many others.
Most gold biscuits are purchased by people wishing to store their assets in gold rather than manufacturers of products who will buy their gold in bars. Buying gold biscuits and bars is almost always cheaper than buying the equivalent weight in coins, and the bigger your purchase, the cheaper it should be. In many countries, you can also avoid paying sales tax or VAT, when buying gold biscuits rather than many coins.
Gold biscuits are sometimes also known as wafers, but will also simply be referred to, by most, as gold bars.