What is the difference between a weighing scale and a weighing balance?
In technical terms, a weighing scale is used to measure weight in accordance with gravity whilst a balance is used to compare the mass of two alternative objects. More recently scales and balances have come to define moreorless the same thing, however one usual way to distinguish the two would be through precision. Balances often have higher readabilities (level of precision) and lower weight capacities compared with scales.
For more information, see Inscale's blog article on the differences between scales and balances.