A bilateral investment treaty (BIT) is kind of like a deal between two countries. It sets out rules that both countries agree to follow when it comes to investment between them. It is designed to make it easier for people in each country to invest in the other country. For example, investors from both countries will know what rights and protections they have, what taxes they need to pay, and how long they can stay in the other country. So the treaty will give investors more confidence in investing in the other country.