Para citar a página de manual bash(1) :
When bash is invoked as an interactive login shell, or as a non-interactive shell with the
--loginoption, it first reads and executes commands from the file/etc/profile, if that file exists.
After reading that file, it looks for~/.bash_profile,~/.bash_login, and~/.profile, in that order, and reads and executes commands from the first one that exists and is readable. The--noprofileoption may be used when the shell is started to inhibit this behavior.<…>
When an interactive shell that is not a login shell is started, bash reads and executes commands from
/etc/bash.bashrcand~/.bashrc, if these files exist. This may be inhibited by using the--norcoption. The--rcfilefile option will force bash to read and execute commands from file instead of/etc/bash.bashrcand~/.bashrc.