A cess is a form of tax levied by the government on tax with specific purposes till the time the government gets enough money for that purpose. 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.
A cess, generally paid by everyday public, is added to their basic tax liability paid as part of total tax paid.
Difference between tax and cess
A cess is different from taxes as it is imposed as an additional tax besides the existing tax (tax on tax). Another difference lies in the way the revenue recovered from cess is maintained. While revenue from taxes like income tax is kept in the Consolidated Fund of India (CFI) and the government can use it for any purposes it deems fit, the revenue coming from cess is first credited to the Consolidated Fund, and the government may then, after due appropriation from Parliament, utilise it for the specified purpose.
Another major difference between central taxes and cess is that the proceeds of a cess may or may not be shared with the state governments, while that of taxes have to be shared.
Various types of cesses levied by the government
The government levies different cesses on services it provides to the public. Some of them are as follows:
Education cess: Collected by the government to provide the mandatory free standard primary education to all citizens.
Health cess: Proposed in 2018 by former finance minister Arun Jaitley to meet the health requirements of below-poverty-line families.  
Road cess or fuel cess: For maintenance of roads and infrastructure.
Clean energy cess: Introduced in 2010, it is a carbon tax on the production and import of coal, lignite and peat, operating on the “polluter pays” principle.
Krishi Kalyan cess: It was introduced in 2016 to provide additional support to farmers for agricultural activities.
Swachh Bharat cess: Introduced in 2014 with the objective of delivering a clean India, it is levied at 0.5 per cent on all taxable services to fund Swachh Bharat initiatives.