What is a shell window. Java basic books always say to open a shell window

The shell window refers to the command line window, and the shell in the traditional sense refers to the command line shell.

1. The shell window under Windows

2. The shell window in Linux is the terminal window.

Shell refers to software (command parser) that "provides a user interface". Similar to command under DOS. The shell receives user commands and then calls the corresponding application. At the same time, shell is also a programming language. As a command language, it interactively interprets and executes commands entered by the user or automatically interprets and executes a series of preset commands; as a programming language, it defines various variables and parameters and provides many high-level functions. Control structures unique to the language, including loops and branches.