On unix-based systems, users typed commands into a program to handle keyboard commands called a

On UNIX-based systems, users typed commands into a program to handle keyboard commands called a shell.
 The UNIX shell is a command-line interpreter that provides a traditional Unix-like command line user interface.
The shell reads the  input after Enter. is pressed and determines the command the programmer wants to execute by looking at the first word of the input. 

The correct answer is: Unix Shell

Explanation:
A Unix shell is a command-line shell or interpreter with the user interface. Users run the operation of the computer by entering commands as text for a command line interpreter to execute, or by creating text scripts of one or more such commands. Hence, the correct answer is Unix Shell.

It should be by long pressing on the name of an answer if not i'm on a pretty old phone so it might be different for me

The type of program is the hierarchical grid