This lecture covers the concept of threads in programming, focusing on their execution in parallel or concurrently, the challenges of shared data access, and the use of locks to prevent issues like deadlocks. Examples include scenarios of multiple threads changing a shared balance in a bank account. The instructor also discusses the importance of thread management in graphical interfaces and web applications, emphasizing the need for separate threads for time-consuming operations. The session concludes with a summary highlighting the benefits and challenges of using threads and locks in programming.