This is because conveyance deeds cover exchange, gifts, lease deeds and mortgage.
You can call all sales deeds conveyance deeds, but not all conveyance deeds are sale deeds. However, when comparing conveyance deed vs sale deed, there is a subtle difference between these two.
As a result, they make the mistake of using it interchangeably. Many individuals confuse between a conveyance deed and a sale deed.