Quantum fluctuations, usually arising from the inherent uncertanity in the quantum fields, are pivotal in understanding the the universe at both the small and large scales. Despite the fact that fluctuations are usually unob-servable rather small, they give significant observable effects during specific epochs under specific conditions. During the early epochs of the universe the fluctuations were scaled, resulting into the primordial density perturbations that gave rise to the large scale structure of universe and the observedinhomogenities. In this paper we study the basic origin, structure, evolution and the imprints of fluctuations during inflationary period resulting into the large-scale structure formation. We use the Mukhanov-sasaki formalism to model scalar perturbations, embedding the theoretical results into observations.Theoretical predictions show almost scale-invariant power spectrum with stringent constraints on the inflationary parameters. It further states that in the very early universe the inflatons that is quanta of primordial field were highly filled in the degenerate quantum state. This carry large potential energythat resulted in an exponential expansion of universe. During post inflationary period the inflaton dominated the Universe’s energy density; they interact among themselves and due to non-linear effects, these inhomogeneities grow which amalgamate into spatially distinguishable patches in our observableuniverse. Our understanding projects us towards the fact that fluctuations play a pivotal role in understanding the structure formation at micro, macro, and far-macro scales. This study also addresses the significance of quantum fluctuations in cosmic evolution and manifests the enduring relevance in addressing some of the profound mysteries of our universe.