Ok, this question is hard. For most people in a casual context, they will mean the same thing. However, in any kind of formal or business setting, they will be different. Wages means something closer to the money someone is owed for work. Most likely referring to how much someone is paid per hour, although not always. Salary means a set amount someone will get paid regardless of how much they work.
For example, an employee on salary of $45,000 per year, will earn $45,000 per year, regardless of how much they work. Someone with a $20 per hour wage, will earn $20 for every hour they work.
Again, this is very formal, almost only used in legal language, or contracts. In casual speech, they would almost certainly be used interchangeably.