Two types of synthetic tokens are created for each synthetic market, which are synthetic long and synthetic short tokens. Synthetic long tokens benefit from the price appreciation 📈 of the underlying asset. Synthetic short tokens benefit from the price depreciation 📉 of the underlying asset.
I.e. Imagine the synthetic market is for Gold. If you buy $100 worth of long Gold tokens, and the price of Gold increase, the value of your token will increase.
These Synthetic Tokens are ERC20 tokens using the Open Zeppelin library which are created dynamically whenever a new synthetic market is created.