Fixed prices are the projects that are well-defined with the reach and job structured and the payment will be realized once at the end of the job.
The customer and professional agreed price before to start working on the project.
It's important to measure the specific goals for both sides. As soon as the job goes on, some deliverables will define the progress of the job. It's crucial to keep clear the reach, time and deliverables before starting work on the project. In this way, you can avoid miscommunication. 😉
On the other hand, if it is not clear what is expected on the project that you applying, some changes are suddenly expected on the project that you are already working on, or even if you must dedicate a large part of your week/month in this project, then it is recommended that you be hired in a more flexible way.