which shell is running?

[shivam99aa]

When we start linux based o/s in GUI mode then as said GNOME is the shell running and when we open the terminal then any shell say bash for here start running.

So that means that in GNOME when we start a terminal then at that time their are actually two shell running simultaneously in the system.Both gnome and bash at the same time.

But what i know is that only one shell run at a time.So what is this .pllzzz clear my doubt on this.

[hagfish52]

GNOME is not a shell, it is a desktop environment and graphical interface that runs on top of Debian. Bash is a command-line shell that gives you direct access to Debian.

[shivam99aa]

If GNOME is not a shell and only an environment then what does this environment takes to communicate to the kernel

[hagfish52]

Perhaps this would help you: Shell (computing) - Wikipedia, the free encyclopedia

The word "shell" among Linux users more commonly refers to command line interface shells like the Bash shell or the Korn shell.

[hagfish52]

Only one "shell" controls the kernel at a given time. When you click on the Terminal window, bash controls the kernel. When you click on the desktop, or an application on the desktop, GNOME controls the kernel.

[masinick]

The more complete truth is that a scheduler, part of the Linux operating system, controls what the kernel does. The kernel is in charge of many things, such as deciding which events take place in a system, which are managed by the scheduler, interacting with devices, through device drivers that are included in the kernel system, controlling both input and output devices. In multiprocessor systems, which many of us have today, several events can take place at the same time. The scheduler will "fork" multiple tasks to manage each different event, and exec, or replace, what it is doing when it has a distinctly different thing to do.

Within processes that a user runs, there can also be similar notions of forks and execs, both of which are interpreted, first by the interpreter, whether it is bash, pdksh, tcsh, or some entirely different command-based interpreter. It may then go and either run a program, another script, or it may make system calls that are part of the operating system. In turn, these events control input, processing, and output in the system.

That is a very simplified view of what a general purpose operating system does.

The shell is typically an interactive script or program that interacts with people using the system, and it can be either interactive or program controlled.
It directly or indirectly interacts with either the kernel or the operating system.