Sorry maybe that is a trivial question, however we are working at work with
some scripts that we are meant to execute for setting the environment before being able to execute other scripts.

Sometime it is required to execute the script like:

. ./script.sh

Do you know what is the difference between executing like "./" and ". ./"

Thanks in advance.

. ./ will run the script in the current shell, it will not spawn a subshell.

What are the consequences? For instance, if I run one script that is setting
the environment like ". ./", I will be able to execute many other scripts & commands later on.
However if I spawn a new subshell, those scripts & commands can not be executed.

Is there any consequences as for user permissons? Sorry, I would like to understand what is going on

Thanks