Non-equilibrium systems have drawn considerable interests due to their ubiquitous presence. Systems of current interests, such as soft matter, active matter and biological systems, are rich areas where non-equilibrium steady state phenomena and transient phenomena to approach the steady state/equilibrium form the basis of their description. They are not only pedagogically important, they are relevant in various technological applications. These fields are rapidly evolving where new ideas and techniques are being introduced all the time. Here we make an attempt to introduce young researchers to this fast and ever evolving research field.