PL/I (Programming Language One) is a high-level programming language developed in the 1960s by IBM. It was designed to combine features from both scientific and business programming languages, making it versatile for various applications. PL/I supports structured programming, exception handling, and has strong data typing, which helps in managing complex data structures. The language is particularly known for its ability to handle both numeric and character data, making it suitable for tasks ranging from data processing to system programming. Although its popularity has declined with the rise of other languages, PL/I is still used in legacy systems, especially in industries like finance and government.