What type of files are stored in /etc (/bin, /var, /sbin, /boot, /lib)?

/etc — system-wide configuration files
/bin — essential binaries needed for single-user mode (e.g. ls, cat, cp)
/sbin — essential system binaries (e.g. init, ip, mount)
/boot — bootloader files (e.g. kernel, initrd)
/lib — libraries essential for the binaries in /bin and /sbin
/var — variable data (logs, spools)