Read this brief article about the programming lifecycle. As you read, consider the following steps of the programming lifecycle: Planning and Analysis, Design, Implementation, Testing and Debugging, Deployment, Maintenance
Three major approaches to software development, which are the means of carrying out the programming lifecycle, have been tried by practitioners. This article compares those three. The most used today are Unified and Agile. These processes help to guide software development projects. They are not software development in and of themselves. Always keep in mind that the goal is to deploy excellent software, not to follow processes.