Memory forensics is a technique used in cyber investigations that allows analysts to capture the current state of a system's memory as an image file. This memory dump can then be analyzed offline to retrieve important artifacts like running processes, open network connections, and recently used files. It is useful because memory stores current system state information that may not be found through other forensic methods. Several challenges in memory forensics include ensuring the integrity of captured memory images and keeping analysis tools compatible with changing operating system structures.