Remember Internet Explorer? JScript was its faithful companion - Microsoft's take on JavaScript with its own quirks. While JavaScript rose to fame in web development, JScript held ground in Windows environments and was commonly used in Active Server Pages (ASP) and Windows Script Host (WSH).
Although JScript shares much with JavaScript, it has its own differences and limitations. It was never intended as a universal solution but rather as a tool for specific Microsoft environments. Today most of JScript's functionality has been superseded by modern technologies, but you may still encounter it when digging into older systems or maintaining legacy code.
So, while JScript is rarely the first choice for new projects, it serves as a reminder of web development history and how we arrived where we are today.