A provisional patent application is a preliminary step and is obtained to get protection before being able to file a complete patent. To get a complete patent, a lot of details of the design and its specifications are required. Filing a provisional patent application doesn’t mean that the patent application will be examined and granted, but the filing date is secured or reserved for the invention.The date of filing the provisional patent application may thus be called an effective filing date. When you are at a stage in your research and development work where it can be disclosed on paper but it’s not a final invention, then you can prepare a description of the invention as a provisional specification and submit it to the patent office to secure the priority date of the invention.