FORTRAN 90 is a high-level programming language that is an evolution of the original FORTRAN language, which was developed in the 1950s for scientific and engineering applications. Introduced in 1991, FORTRAN 90 brought significant improvements, including support for modular programming, array handling, and improved input/output capabilities. One of the key features of FORTRAN 90 is its ability to handle complex data structures and perform operations on entire arrays without the need for explicit loops. This makes it particularly useful for numerical computations and simulations in fields such as physics, engineering, and computational science.