A more thorough explanation:

A Joint Resolution of Congress is a type of legislative measure that requires the approval of both the Senate and the House of Representatives. It is one of four principal forms of proposals introduced in Congress, along with bills, concurrent resolutions, and simple resolutions.

Joint resolutions are submitted to the President for signature into law, just like bills, with one exception: proposals to amend the U.S. Constitution. Joint resolutions that are used to propose constitutional amendments require a two-thirds affirmative vote in each house but are not submitted to the President. Instead, they become effective when ratified by three-quarters of the states.

Joint resolutions originating in the Senate are designated by the letters "S.J.Res." followed by a number, while those introduced in the House of Representatives are designated "H.J.Res." followed by a number.

For example, in 2019, Congress passed a joint resolution to terminate the national emergency declared by President Trump in order to secure funding for a border wall. This joint resolution was introduced in the House of Representatives as H.J.Res. 46 and in the Senate as S.J.Res. 10. It required a two-thirds majority vote in both chambers to pass, and it was ultimately vetoed by the President.

Another example of a joint resolution is the 26th Amendment to the U.S. Constitution, which lowered the voting age from 21 to 18. This joint resolution was introduced in Congress in 1971 and required a two-thirds majority vote in both the Senate and the House of Representatives. It was then sent to the states for ratification and was ultimately ratified by three-quarters of the states, becoming the 26th Amendment to the Constitution.