Understand Electronic Dispersion: Definition & Examples

[nouha]

TL;DR

I am not being able to understand what is the electronic dispersion exactly, I have came across it in few papers and I haven't find any resource that explained it clearly and simply.

I am not being able to understand what is the electronic dispersion exactly, I have came across it in few papers and I haven't find any resource that explained it clearly and simply.
I've came across 'the electronic dispersion is linear' and 'electronic dispersion is parabolic' and some graphs about it but I still didn't understand what is this electronic dispersion exactly, how do we get it and why it is so important

 

[Demystifier]

I've came across 'the electronic dispersion is linear' and 'electronic dispersion is parabolic'

Sound like it is just the dispersion relation (formula that expresses frequency as a function of wave vector $k$) for electrons.