In a recent class session, the teacher reviewed material on binary trees and then discussed the importance of balancing binary trees. The teacher explained that the height of a binary tree represents the number of nodes in the tree and that it is important to balance the tree by making sure the height of the left and right subtrees are as close as possible. The teacher provided examples of balanced and unbalanced binary trees and asked students to come up with their own solutions to balance an unbalanced tree. The session ended with the teacher asking students if they had any questions or concerns.