Okay kiddo, let me explain Lend-Lease and Sherman tanks in a way that's easy for you to understand.
During World War II, many countries were fighting against each other. The United States wanted to help their allies (friends who they were fighting with) by giving them weapons and supplies to help them win the war. This was called Lend-Lease. The idea was that the US would lend or lease military equipment to other countries to help them fight the war.
One of the weapons they gave to their allies were tanks. The US was really good at making tanks, and they made a lot of them. One of the most famous tanks they made was called the Sherman tank.
The Sherman tank was really important during the war because it was reliable and could go pretty fast. It also had a lot of firepower, which means it could shoot really powerful weapons and blow up enemy tanks and buildings.
The US sent a lot of Sherman tanks to their allies through the Lend-Lease program. This helped their friends fight against their enemies and win the war.
So, to sum it up, Lend-Lease was when the US lent or leased weapons and supplies to their allies during World War II, and one of the weapons they gave was the reliable and powerful Sherman tank.