This chapter builds upon the concepts introduced in Chapters 1 and 2, further exploring traditional communication and semantic communication from an architectural perspective. In the section on traditional communication frameworks, we introduce the fundamental modules of digital communication systems. By explaining the process flow of bits and signal processing methods, readers can gain a necessary understanding of the basic operations in communication systems required in semantic communication research. While discussing traditional digital communication, we also emphasize the roles and research status of corresponding modules in semantic communication. In the section on semantic communication frameworks, we start with an overview of the architecture. Based on this, we introduce discussions on joint semantic-channel coding, semantic information transmission, as well as computational resources and semantic knowledge bases. Through this section, we aim to highlight the key concepts and design principles of semantic communication and inform readers that many related research efforts are ongoing.