STS stands for both “Ship to Ship” and “Ship to Shore”. When cargo loads to a vessel directly which is discharged from another vessel without keeping them in storage it becomes ship to ship operation. When a discharging happens to the land side it becomes ship to shore. Explaining this further, cargo can discharge to another vessel or send to the storage of the port or direct discharge to a truck. Discharging to a truck means discharging from the waterfront to the landside.