Answer - Although most commonly known for analysing the input line as well as initiating the execution of the program entered by the user, the Shell has various other responsibilities. A brief description of this is given to you below; The shell is responsible for the execution of all the programs by analysing the line and determining the steps to be performed and then initiate the execution of the selected program. The shell allows you to assign values to the variables when specified on the command line. It also performs Filename substitution. The shell takes care of input and output redirection. The shell performs pipeline hook-up by connecting the standard output from the command preceding the ‘|’ to the standard input of the one following ‘|’. The shell provides certain commands to customise and control environment. The shell has its own built-in integrated programming language which is typically easier to debug and modify.