* /etc/environment file
The first file that the operating system uses at login time is the /etc/environment file. The /etc/environment file contains variables specifying the basic environment for all processes.
* /etc/profile file
The second file that the operating system uses at login time is the /etc/profile file.
* .profile file
The .profile file is present in your home ($HOME) directory and lets you customize your individual working environment.
* .env file
The first file that the operating system uses at login time is the /etc/environment file. The /etc/environment file contains variables specifying the basic environment for all processes.
* /etc/profile file
The second file that the operating system uses at login time is the /etc/profile file.
* .profile file
The .profile file is present in your home ($HOME) directory and lets you customize your individual working environment.
* .env file
A fourth file that the operating system uses at login time is the .env file, if your .profile contains the following line: export ENV=$HOME/.env
/etc/environment -> /etc/profile ->* .profile -> * .env
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