The official title is the "Treaty of Amity Commerce and Navigation between His Britannic Majesty; and The United States of America." Normally people go ahead and shorten it to the Jay Treaty or Jay's Treaty. (Probably because TOACANBHBMATUSOA is a super-awkward acronym.)

As you probably guessed, that "Jay" is for John Jay, one of the signers of the Treaty of Paris and the Chief Justice of the Supreme Court. Basically, there was still a lot of tension between Great Britain and the U.S. at the time. British military outposts were a problem and the British had a habit of interfering in trade.

The treaty got the British to back off and successfully averted war, but it wasn't popular. Jay only got the British to abandon some of their northwestern posts (which technically should have already been done, as per the Treaty of Paris), and gave the U.S. "most favored nation" status with Great Britain.

So, yeah. Not much.

But it did accomplish avoiding a war with Great Britain, which probably wouldn't have gone well the second time around.