Cement is a chemical substance, a binder that plays a vital role in the construction process. Cement is seldom used alone, but rather to bind aggregates. There are different types of Cement available for different construction works, primary classification includes only the following 2 types:

1.  Ordinary Portland Cement (OPC): OPC is the most commonly used type of cement in the world. OPC comes in a range of specifications to suit a variety of conditions and applications such as dry-lean mixes, general-purpose ready-mixes and even high-strength pre-stressed and pre-cast concrete. OPC is available in OPC-43 Grade & OPC-53 Grade. It is commonly utilized in reinforced concrete buildings, bridges, and pavements, as well as in areas with standard soil conditions.
2.   Portland Pozzolana Cement (PPC): Portland Pozzolana Cement is a variation of Ordinary Portland Cement. Pozzolana materials namely fly ash, and volcanic ash, are added to the OPC so that it becomes PPC. PPC has lower initial strength compared to OPC but provides better workability and finishing, but the strength of PPC is good than OPC in the long term. PPC provides greater resistance to chemicals. PPC cement is generally used for plastering, masonry and waterproofing. 

There are many other Blended and other special cement used for specific purposes like Portland Slag Cement (PSC), Rapid Hardening Cement, Extra Rapid Hardening Cement, Low Heat Cement, Sulphates Resisting Cement, Quick Setting Cement, Coloured Cement, High Alumina Cement (Calcium Aluminate Cement (CAC) or aluminous cement) and Blast Furnace Slag Cement