This chapter presents finite blocklength analyses for point-to-point matched communication, covering topics including lossless and lossy source coding, channel coding, and joint source-channel coding. This chapter sets the theoretical foundation for low-latency communications. A take-home message is that finite blocklength analyses provide a tight approximation to the performance of optimal codes with short blocklengths, while classical Shannon theoretical results are inaccurate for low-latency communication. The readers can quickly grasp the core theoretical results of low-latency point-to-point matched communication systems.