A carat is a unit measure for how much gold is in a metal.
Pure gold is 24 carats, but this is way too soft to be used to make jewellery. So it’s more often than not alloyed with other harder metals such as silver or copper.
9 carat gold means that 9 parts of the 24 are pure gold (37.5%) the other 15 parts (62.5%) are made up of silver & copper.14 carat means that 14 parts of the 24 are pure gold (58.3%) etc…
We use 9ct gold in all of our jewellery as it keeps our price point accessible, whilst still being a beautiful and durable form of gold.