What does cess mean?

Cess is a form of tax charged/levied over and above the base tax liability of a taxpayer. A cess is usually imposed additionally when the state or the central government looks to raise funds for specific purposes. Different from the usual taxes and duties like excise and personal income tax, a cess is imposed as an additional tax besides the existing tax (tax on tax). 

For example, the Swachh Bharat cess is levied by the government for cleanliness activities that it is undertaking across India.

Further Reading:

• Value Added Tax (VAT)
• Taxation in India