The software development life cycle (SDLC) in this manual testing tutorial is a method that establishes a framework for software development. Within the SDLC, there are several phases, each with its own set of activities. It enables the development team to build, design, and execute high-quality products.

In SDLC all the Requirements are translated into design, design into development, and development into testing, with the final product being delivered to the client following testing.

1. Requirement Phase

For both the creating team and the project manager, this is the most critical phase of the software development life cycle. During this phase, the client specifies the product's or software's requirements, specifications, expectations, and any other particular requirements. All of this is obtained by the service provider's business manager, project manager, or analyst.

To establish the load of activities, the need comprises how the product will be utilised and who will use it. This phase's knowledge is crucial for designing the product to meet the needs of the consumer.

2. Design Phase

According to the requirement phase, the design phase comprises a complete analysis of new software. Because the conceptual design of the system is turned into physical design, this is a high priority phase in the development life cycle of a system. The requirement phase produces a list of things that must be done, and the design phase determines how these requirements will be met. This step involves deciding on all necessary essential tools, such as a programming language like Java,.NET, PHP, a database like Oracle, MySQL, and a mix of hardware and software to offer a platform on which software may execute without error.

For documenting the system design, several methodologies and tools such as data flow diagrams, flowcharts, decision tables etc are employed.

3. Build /Development Phase

The next stage is to incorporate the design into the construction of a software system when the requirement and design phases have been completed successfully. Work is divided into small units in this phase, and coding begins by a team of developers in accordance with the design negotiated in the previous phase and the client's requirements discussed in the requirement phase to generate the intended outcome.

Back-end developers execute back-end coding according to the required operations, while front-end developers create simple and attractive GUIs and necessary interfaces to communicate with back-end processes. Everything is carried out in accordance with the project manager's instructions and requirements.

4. Testing Phase

Testing is the final phase in the development of a software system. After receiving the built GUI and back-end combo, this phase involves testing it against the requirements specified in the requirement phase. Testing examines whether or not the programme is producing the desired results as outlined in the requirements phase. To begin the test, the Development team creates a test plan. This test strategy comprises integration-testing, unit-testing, acceptability-testing, and system-testing, among other types of testing. This phase also includes non-functional testing.

If there are any bugs in the software or it isn't performing as expected, the testing team informs the development team in detail about the problem. If the defect is valid and worth fixing, it will be corrected, and the development team will replace it with a new one, which will also need to be verified.

5. Deployment/ Deliver Phase

After software-testing has yielded a satisfactory result and there are no residual difficulties with the software's operation, it is released to the customer for usage.

Customers are encouraged to begin beta testing as soon as they acquire the product. Customers can request any improvements not existing in the product but specified in the requirement document, as well as any additional GUI adjustments to make it more user-friendly, during beta testing. Aside from that, if a customer encounters a defect while using the software, the problem will be reported to the product's development team, who will resolve the issue. If the problem is serious, the development team will fix it right away; if it isn't, it will have to wait until the next release.

The software was finally distributed to the end-user after all issues and changes were resolved.

6. Maintenance

The maintenance phase of the SDLC is the final and longest, as it is the process that continues until the software's life cycle is completed. When a consumer begins to use software, actual difficulties begin to arise, and there is a need to resolve these issues. This phase also entails making changes to hardware and software in order to maintain operational effectiveness, such as improving performance, improving security features, and meeting client expectations in the near future. Maintenance is the process of looking after a product from time to time.

So, these are the six phases of the software development life cycle (SDLC), which govern the software development process. All of these phases are required; without them, none of the

improvements would be feasible, as development continues throughout the software's lifetime with the maintenance phase.