These two files looks pretty similar. What is the purpose of these files ?

Thanks

things like:
PATHS
custom PS1 strings
aliases
....etc,are stored in these files...

One important distinction is that bash_profile is read when you loggin whereas bashrc is read each time you open a bash shell after youve logged in.

When you start a login shell, bash consults the following files in the specified order:
1. /etc/profile
2. ~/.bash.profile
3. ~/.bash_login
4. ~/.profile
When you start a nonlogin shell, bash consults only one startup file, ~/bash.rc.

What do you mean by "nonlogin shell"? When OS starts?

Just think of a non-login shell as when you open a new instance of bash up after youve logged in - each time you do this the ~/.bashrc file is read - this file is good for putting Aliases in amongst other things.

is there any command that can be use for restarting the .bash_profile, so don;t have to restart the whole pc?
i mean, like in windows, you can restart the 'explorer' only if you made changes in registry....

TIA.

On the command line:-
. .bash_profile

What .(dot) before .bash_profile does?

It's been a long time, but for completeness:

If you run it like:
$ .bash_profile
it creates a new process to run the file. Any aliases created will be valid only for that process. When the file is finished running, that process ends, and the new aliases expire.
If you run it like:
$ . .bash_profile
it runs it in the current process. When the file is finished executing, the new aliases are still valid.

See $man . OR $man source

.bash_profile vs .bashrc
by Josh Staiger

WHEN working with Linux, Unix, and Mac OS X, I always forget which bash config file to edit when I want to set my PATH and other environmental variables for my shell. Should you edit .bash_profile or .bashrc in your home directory?
You can put configurations in either file, and you can create either if it doesn’t exist. But why two different files? What is the difference?
According to the bash man page, .bash_profile is executed for login shells, while .bashrc is executed for interactive non-login shells.
What is a login or non-login shell?

When you login (type username and password) via console, either sitting at the machine, or remotely via ssh: .bash_profile is executed to configure your shell before the initial command prompt.
But, if you’ve already logged into your machine and open a new terminal window (xterm) inside Gnome or KDE, then .bashrc is executed before the window command prompt. .bashrc is also run when you start a new bash instance by typing /bin/bash in a terminal.
Why two different files?

Say, you’d like to print some lengthy diagnostic information about your machine each time you login (load average, memory usage, current users, etc). You only want to see it on login, so you only want to place this in your .bash_profile. If you put it in your .bashrc, you’d see it every time you open a new terminal window.
Mac OS X — an exception

An exception to the terminal window guidelines is Mac OS X’s Terminal.app, which runs a login shell by default for each new terminal window, calling .bash_profile instead of .bashrc. Other GUI terminal emulators may do the same, but most tend not to........
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PS: all credit goes to Josh Staiger
I just connect the dots

yours

Pavlos