Lockfiles and pid files are essential tools used in programming to manage process concurrency and ensure data integrity. A lockfile allows only one instance of an application to run at a time, preventing data corruption during operations like database access or file manipulation. However, traditional lockfile methods can lead to issues when an application terminates unexpectedly, leaving orphaned lockfiles that require manual cleanup. To address this, pid files can be implemented, which contain the process ID of the running application, allowing for automated recovery and cleanup of orphaned files. By checking if the process associated with a pid file is active, developers can decide whether to remove the pid file, thus simplifying the management of running processes. The lesson outlines the steps for creating pid files, incorporating process management techniques, and presents a functional approach to implementing file locking mechanisms.