This lecture covers the file system abstraction, focusing on the organization and management of files and directories within a computer system. It begins by explaining the need for long-term information storage and how files serve as named collections of related information stored in secondary storage. The instructor discusses the two main components of the file system: files and directories, emphasizing the importance of metadata associated with files, such as size, owner, and permissions. The concept of inodes as unique identifiers for files is introduced, along with the inode table that manages metadata and data locations. The lecture further explores the user perspective of file names and the hierarchical organization of directories, illustrating how files are accessed through path names. The process view is also examined, detailing how file descriptors are used to manage open files and perform operations like reading and writing. The lecture concludes with an overview of the file system API, including key system calls for file management and operations.