These files contain the aliases and environmental variables made available to Bash running as a user shell and to all Bash scripts invoked after system initialization.
systemwide defaults, mostly setting the environment (all Bourne-type shells, not just Bash )
systemwide functions and and aliases for Bash
user-specific Bash environmental default settings, found in each user's home directory (the local counterpart to /etc/profile)
user-specific Bash init file, found in each user's home directory (the local counterpart to /etc/bashrc). Only interactive shells and user scripts read this file. See Appendix G for a sample .bashrc file.
This does not apply to csh, tcsh, and other shells not related to or descended from the classic Bourne shell (sh).