Tax havens are jurisdictions that offers favorable tax conditions and secrecy to taxpayers as relative to other jurisdictions. There is no generally accepted definition of a tax haven, but commonly associated with such jurisdictions are low or no-taxes, no withholding taxes, and strict laws on secrecy.
Harmful tax practices refers to countries issuing highly favourable tax rulings and implementing preferential tax rules/regimes to attract foreign income, thereby eroding the tax bases of other countries.