VAX, short for "Virtual Address eXtension," is a series of computer architectures developed by Digital Equipment Corporation (DEC) in the late 1970s. It was designed to support complex computing tasks and was widely used in business and academic environments. VAX systems are known for their ability to handle large amounts of data and run multiple applications simultaneously. The VAX architecture introduced the concept of virtual memory, allowing programs to use more memory than physically available. This innovation improved efficiency and performance in computing. Over time, VAX systems became popular for their versatility and reliability, influencing later computer designs and architectures.