Let us see the difference with these two scripts:
~/.bashrc file runs every time you open a new non-login bash shell such as xterm / aterm, and ~/.bash_profile runs only with login shells i.e when you first log in into system.
/etc/profile – System wide global profile
The /etc/profile file is systemwide initialization file, executed for login shells. You can edit file using vi (login as root):
# vi /etc/profile