Finite State Machine (FSM) is used to solve problems in math, games, and practical skills by making use of regions and transformers to model individual processing units and link them to create a complete sequence of operating conditions, which can be handled easily. Owing to their logical structure, FSMs are considered to be ideal tools for structural and behavioral modeling of software applications that assist in various phases of SDLC(Software Design Life Cycle) like Requirement Specifications, Design, Testing, etc. Software testing cost is a function of the size of the constructed test suite, given as, the number of tests and their combined length. FSMs are deployed as a smart tool to get a set of prioritized test suits that not only verify the user value-based system features rather reduce the testing cost to a major extent. This paper aims to provide comprehensive knowledge about what is FSM (Finite State Machine) and how it can be incorporated to model some software applications. For further illustration, a case study of the Daraz App has been discussed for which both simple and Markovian Operational Profiles (MOP) have been formed using the Mealy models for the graphical, tabular, and list representations. We aim that this study proves to be a productive contribution for individuals working with different types of FSMs to get an in-depth understanding of model construction and its implication for software testing.