Section 2. This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by the legislatures of three-fourths of the several States within seven years from the date of its submission to the States by the Congress.
The Twenty-Second Amendment set presidential term limits at two terms.
This video recounts the history behind the ratification of the 22nd Amendment. It talks about how President George Washington set the ground for the custom of presidents serving two terms until being challenged by President Grant and President Roosevelt. The 22nd Amendment was created to prevent this from happening again.