What is the difference between PIM sparse mode and PIM dense mode?

Protocol Independent Multicast (PIM) sparse mode and dense mode are two different multicast routing mechanisms. Sparse mode uses distribution trees and is designed for networks where multicast groups are sparsely distributed across the network, minimizing unnecessary traffic. In contrast, dense mode floods the network with multicast traffic and then prunes back the branches where there are no interested receivers, which can lead to inefficient use of bandwidth. References := CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide