Provisional Patent?

As noted by Adam, there is no such thing as a provisional patent - there is only a provisional patent application which can, by itself, never ever lead to a patent because the provisional patent application is never examined. You have to effectively convert the provisional patent application into a non-provisional patent application or a PCT patent application which will not only "open the door" to permit you to obtain patents in countries other than the US but you can effectively file a US national stage application at the appropriate time through means of PCT, and this has to be done within one year of filing your provisional patent application. If you are intending to obtain foreign patents, while claims in the provisional patent application are not necessarily required, it is highly desirable because, for example, in Europe, they effectively require the provisional application to have had claims, so to avoid any possibility of your priority of your provisional application not being "accepted" or the priority being "denied", I would highly suggest that you include claims. Another important consideration is that for the provisional application to serve as a basis for priority, the application must, as with a non-provisional application, comprise an enabling disclosure which, for all intents and purposes, means that it must be complete, accurate, and thorough. And this is true even if you are still in a development stage - file a provisional application on whatever you have already developed, and if you develop improvements, or other embodiments, you can file additional provisional applications for the additional improvements or embodiments. An easy and efficient way to do this is to use your first provisional application as the basis for your second provisional application, and then your non-provisional or PCT application can effectively be your second provisional application because that second application will contain everything that was in your first provisional application plus the improvements or new embodiments. Note that you must still file your PCT or non-provisional application within one year from the filing date of the first provisional application.