Mole concept explain

One mole of any substance contains Avogadro's number of particles, which is approximately $6.022 \times 10^{23}$. These particles can be atoms, molecules, ions, or electrons.

For example, one mole of carbon atoms contains $6.022 \times 10^{23}$ carbon atoms. One mole of water molecules ($H_2O$) contains $6.022 \times 10^{23}$ water molecules.