Hydrogen bond is defined as a weak bond that results from electrostatic attraction taken place between hydrogen of one molecule and electro-negative atom of same or different molecule.
In water, partial negative charge is present on oxygen atom which attracts the partial positive charge present on hydrogen atom of other water molecule. This attractive interactions lead to the formation of inter-molecular hydrogen bonding.
Water molecules are bonded by strong hydrogen bonding between the less electronegative hydrogen atom and the electronegative oxygen atom. Oxygen atom withdraws the electron density towards itself and thus acquire a partial negative charge and hydrogen acquires a partial positive charge. The opposite charges attract each other and result into hydrogen bonds.
Ionic bond is formed the transfer of electrons between two atoms.
Covalent bond is formed by the sharing of electrons between two atoms.
Chemical bond is formed either by sharing of electrons or by transfer of electrons.