How do bonds work?

Hint: Bond-formation can be classified into many types such as covalent bonding, ionic bonding, coordinate bonding, etc. however, the basic output of these bond-formation types is the same, i.e. bind two different or even similar atoms together. Essentially it is a type of binding force and thereby functions in the similar manner.

Complete answer:
A chemical bond is defined as a strong force of attraction which helps in holding atoms together in a molecule or complex or crystal. These forces of attraction are formed only either by sharing or by transferring of electrons between two atoms amongst which two bonds are to be formed .
There are mainly three types of bonding:
1) ionic bonding: in this, there is an electrostatic force of interaction between the two atoms which are bonded in the molecule or crystal. There is formation of ions in this type of bonding, i.e. cations and anions. Example: $NaCl$ molecule has ionic bonding.
2) covalent bonding: in this type of bond formation in which there is equal sharing of electrons between both the atoms to be formed as molecules. There may be a little difference in the electronegativity and thus giving birth to the dipole moment. Example: $C{H_4}$ molecule.
3) coordinate bonding: this is the type of bonding in which the donor atom gives an entire pair of electrons to the acceptor atom and thus this results in the formation of bond between the two atoms. This type of bond is majorly seen in complex molecules like $PtC{l_4}$ .

Note:
The basic need of the formation of bonds is that every atom wants to stay stable and with the lowest energy. In chemistry, it is, through theoretical as well as practical, tested that the noble gas configuration is the stable configuration for any atom. Thereby, the atoms undergo bonding through donating/ accepting or sharing electrons to attain this stability.