Two-dimensional (2D) Systems also called *Layered Materials* also called *2D world*

2D materials are classified into 5 subclass. They are:
1. Graphene
2. MXenes
3. Transition Metal Dichalcogenides(TMDCs), sometime abbreviate TMDs
4. Transition Metal Oxides (TMOs)
5. Hexagonal Boron-nitride (h-BN)

All these 2D materials are ONE or Several atoms thick and all are derived from their 3D counterparts. For instance, graphene derived from 3D graphite block and similarly MXenes derived from the MAX phases.

Application of these materials are numerous, few of them are:

Crack healing in air, Lithium ion battery, Supercapacitors, electromagnetic interference shielding, spintronics, optoelectronics, flexible electronics, energy harvesting, DNA sequencing and personalized medicine.....