what is the use of peltier effect in practical life

Thermoelectric effects can be used to make solid-state refrigeration devices, or to sense temperature differences, or to convert thermal energy directly into electricity. This section explains the underlying principles.
There are three different thermoelectric effects. They are named the Peltier, Seebeck, and Thomson effects after the researchers who first observed them. Thomson is better known as Kelvin.
These effects are not at all specific to semiconductors. However semiconductors are particularly suitable for thermoelectric applications. The reason is that the nature of the current carriers in semiconductors can be manipulated. That is done by doping the material as described in section6.23. In ann-type doped semiconductor, currents are carried by mobile electrons. In ap-type doped semiconductor, the currents are carried by mobile holes, quantum states from which electrons are missing. Electrons are negatively charged particles, but holes act as positively charged ones. That is because a negatively charged electron is missing from a hole.

Thermoelectric effects can be used to make solid-state refrigeration devices, or to sense temperature differences, or to convert thermal energy directly into electricity. This section explains the underlying principles.
There are three different thermoelectric effects. They are named the Peltier, Seebeck, and Thomson effects after the researchers who first observed them. Thomson is better known as Kelvin.
These effects are not at all specific to semiconductors. However semiconductors are particularly suitable for thermoelectric applications. The reason is that the nature of the current carriers in semiconductors can be manipulated. That is done by doping the material as described in section6.23. In ann-type doped semiconductor, currents are carried by mobile electrons. In ap-type doped semiconductor, the currents are carried by mobile holes, quantum states from which electrons are missing. Electrons are negatively charged particles, but holes act as positively charged ones. That is because a negatively charged electron is missing from a hole.