Is Peoples A Word?

It sounds funny I know, but it is.

Yes but it's usage is usually more formal or old (for example, it's used in most translations of the Bible). The word 'people', like 'fish', can be either singular or plural. Peoples is simply an alternative plural to people. Don't confuse it with people's or peoples', though.

Hope this helps.

It's often used in an expression like "the peoples of the world" to emphasise the many cultural differences that exist.

It does not make sense, but yes it is.