A baseball pass in basketball is when the ball travels from one teammate to another. The ball can either travel through the air or bounce off the floor. What differentiates it from a normal pass is the delivery. A normal pass can also travel through the air or bounce on the court, but is typically thrown with two hands. A baseball pass is thrown using only one hand.
A baseball pass is usually for longer distances or when you need to make a quicker pass. It gets to your intended target a lot faster than a typical chest or bounce pass. The major thing to be mindful is that because it is a pass thrown with just one hand, you have less control of where the ball will go. Don't overestimate your abilities with a baseball pass and overthrow your teammate or miss your teammate badly and turn the ball over to the other team.