Definition: A provisional patent application is a type of interim utility patent filed with the USPTO. You can file for a provisional patent without including any formal patent claims, oath or declaration, or any information disclosure (prior art) statement.
The keyword in provisional patent application is "provisional". A provisional patent application only gives one year of protection. After that you must file for a non-provisional patent or abandon your patent.
The USPTO created provisional patent applications as a means to establish an early effective filing date for a non-provisional patent application, which helped balance American patent law with the patent laws of other countries. It also allows the term "Patent Pending" to be used.

