What is hydrogen bond? Explain the types of hydrogen bonds with example?

Hydrogen bond : The weak electrostatic force of attraction between H-atom and highly electronegative atom (F, O, N) of same or different molecules is called as hydrogen
bond. Hydrogen bonds are two types
1. Inter molecular hydrogen bond
2. Intra molecular hydrogen bond
Inter molecular hydrogen bond :
Hydrogen bond formed between two different polar molecules is known as inter molecular
hydrogen bond.
Ex : H₂O, HF, NH₃ etc.
$\mathrm{H}-\mathrm{F}---\mathrm{H}-\mathrm{F}---\mathrm{H}-\mathrm{F}$
Intra molecular hydrogen bond :
Hydrogen bond formed within the same molecule is called as intra molecular hydrogen bond.
Ex: Ortho nitro phenol, ortho hydroxy benzaldehyde.