`ls'` command opening another shell

Question

I typed ls' (ls with single quote ) and it opened another shell. Which type of shell it is? what is it used for?

below is the reference:

Answer 1

It's still the same shell. By opening a single quote, you expressed the intention to enter an argument that can optionally span multiple lines. The shell is giving you the opportunity to write however lines you want, until you type a closing '.

Consider this for example:

$ echo '
> hello
> there
> '

This is echo followed by a single argument composed of four lines. Output:

hello
there