This lecture covers the concept of monitors as a synchronization construct in concurrency. Monitors provide mutual exclusion and cooperation among threads, allowing them to wait for specific conditions. The instructor explains how monitors offer a high-level abstraction for synchronization, combining mutual exclusion with conditional synchronization. Examples such as the one-place buffer illustrate the need for coordination among threads using monitors. The lecture also discusses the implementation of monitors in Scala, highlighting the synchronized statement's dual role as a lock and a monitor. Additionally, the use of wait, notify, and notifyAll methods within monitors for thread synchronization is explained.