[AdiDex]

If you have to differentiate between Inductive effect and Mesomeric effect then  how will you .??
Its not about, in mesomeric effect includes resonance , it does not depends upon distance , whereas inductive effect don't .!
Both are permanent effects...!!
I know these things ..!!

My question is "what is there origin " , "why they exist" ...??
Its about basic..!!
Please someone help me..!

*{MOD Edit -- add useful title}

[mjc123]

Crudely, sigma vs. pi.
Inductive effect is due to an atom attracting electron density to itself due to its electronegativity (or repelling due to electropositivity), and acts chiefly through sigma bonds.
Mesomerism arises from the ability to delocalise charge through the overlap of p orbitals to give extended pi systems. It may give opposite results from inductive effect, e.g. N or O can share a lone pair and gain a (partial) positive charge.

[AdiDex]

Is this right to say that..
Due to mesomeric  effect no. Of resonatic structure increases , which brings stability to the system.

But due to this charge separation also introduced in the system..
So what about that...??