This document defines the features, functions, and conditions for your software project. It needs to include the interests of all stakeholders – to define the business requirements, key metrics, user personas, and more. It details the technologies and programming languages that should be used, and a lot more. The University of Colorado, Colorado Springs has a free SRS template that you can download. It is a detailed document, but it will be used throughout the entire development effort of your project.
Companies lacking technical expertise may resort to identifying comparable software already on the market as a starting point. An example of what you are looking to create is usually sufficient for an IT staffing agency to connect you with someone who can help you develop the SRS. It is still needed because it identifies the positions, skill sets, and expertise of the people you will need – software developers, software engineers, full-stack developers, UI/UX designers, data scientists, machine learning specialists, etc.