What are the four principles of a sound tax system according to Adam smith?

According to Adam Smith, the four principles of a sound tax system are equity, certainty, convenience, and efficiency. Equity means that taxes should be fair and based on an individual's ability to pay. Certainty refers to taxpayers knowing how much they owe and when, while convenience emphasizes that the tax payment process should be straightforward. Lastly, efficiency indicates that taxes should not hinder economic growth or productivity.