What is ISAM used for?

ISAM, or Indexed Sequential Access Method, is a database file organization that is commonly used in database management systems. But what specific purposes does ISAM serve? Is it primarily for quick data retrieval, or does it offer other benefits as well? Could you elaborate on the types of applications that typically utilize ISAM for their database needs? And how does ISAM compare to other database organization methods in terms of performance and efficiency?