The Waterfall Model was the first to implement a Process Model. The waterfall model is a classic technique used in the life cycle of software development to generate a system with a linear and sequential approach. It is called a waterfall because the model systematically develops in a downward fashion from one phase to another. This model is divided into different stages, and one phase output is used as the next phase input. Each process must be finished before the next phase begins, so the phases do not overlap. The entire process of software development is split into different phases under the Waterfall method. The result of one phase serves sequentially as the reference for the next phase. This means that every stage in the cycle of creation only starts when the previous step is complete. The waterfall model is a sequential design process where progress is seen as slowly flowing downward like a waterfall. The Waterfall Model illustrates the process of software development in a linear sequential flow and is therefore also referred to as a Linear-Sequential Life Cycle Model. Requirements: The first step includes knowing what needs to be planned and what its purpose, function, etc. is. The input and output parameters, or the final product, are analyzed and labeled here. Design: In this process, requirement requirements are studied from the first process, and device design is prepared. System Architecture helps determine hardware and device specifications and helps define overall system design as well. Now the software code is generated to be written in the next level. Development: The system is first built in small programs called units with inputs from system design which are implemented into the next step. Each unit is built and evaluated for its functionality known as Unit Testing. Testing: After testing each unit all the units created during the implementation process are incorporated into a system. The built software needs to go through continuous software testing to decide whether any bugs or errors are present. Testing is performed so that no problem faces the system during program installation. Deployment: Once the functional and non-functional testing has been performed, the product is either deployed in the customer environment or released to the market. Maintenance: This phase takes place after deployment and includes making devices or individual component adjustments to alter attributes or enhance performance. Such changes occur either from customer-initiated demands for improvement or from vulnerabilities found during the system’s live use. The customer provides routine maintenance and support for the program built Advantages of the Waterfall Model 1) The benefit of the production of waterfalls is that it enables departmentalization and control. A timeline can be set with deadlines for each production point, and a product can progress one by one through the phases of the development cycle model. 2) The waterfall model moves through phases that are easy to grasp and describe, and is therefore easy to use. 3) Due to the rigidity of the model, it is simple to handle-each step has clear outcomes and a review process. 4) Phases are processed and completed in this model one at a time and do not overlap. The waterfall model fits best with smaller projects where there is a very strong understanding of the needs. Disadvantages of Waterfall Model 1) Time and cost estimates for each step of the production cycle are difficult. 2) If an application is in the development process, it is very difficult to go back and modify something which was not well-thought-out in the design phase. 3) Not a suitable model for object-oriented and complex projects. 4) Not ideal for projects where there is a moderate to high chance of change in the specifications.