A US non-provisional patent application is the best choice when your invention is nearing completion and you know the final implementation details. It's a full patent application that is examined by the USPTO and may issue into a patent. It is more involved than a provisional patent and requires formalities and a full claim set, which represents your legal claim to what is new in your invention.
The detailed description, figures, claims and abstract go to make the specification. Once issued it will give you full protection for your invention in the United States.
If you desire international protection, you should file international applications or an International (PCT) Patent: Learn more here.
Once filed, it enters the examination process at the USPTO. This process involves an examiner conducting extensive searches and analyzing the application in light of discovered prior art or any deficiencies with the application. Ultimately, it is this examination that will result in a determination as to the novelty, utility, and non-obvious attributes of your invention.
Non provisional patents are published 18 months from the earliest filing date for the invention, while provisional applications are not published. If the nonprovisional patent application passes examination at the USPTO, and all issue fees are paid, the office will issue a US patent. A granted US patent is valid for 20 years from the date of filing and will entail periodic payment of maintenance fees in order to keep it active.
Keep in mind that you do not want to publicly disclose your invention to anyone before you have an application on file. Not only do you run the risk of having someone steal your rights, but in the US you must file within 12 months of the public disclosure. For foreign protection, you may immediately be barred from seeking patent protection. So do not put it on a website, show it on YouTube, take it to a tradeshow, or write an article in a magazine about it until you have your filing date!