it is a configaration directory in unix system.max file is in form of database.for example file /ect/passwd is kept information of user name,gruop name,uid,gid, home directory and shell.
In file /etc/passwd
With program fdisk (or cfdisk etc).
/etc/sysctl.conf
"Types" of Linux are Called Linux Distributions. Linux by itself is only a kernel, you need more than that for a full system, to get this, distro's were develpoed to include all of this to make a Linux system easier to install. Popular Distro's Are Ubuntu, Debian, Fedora, RHEL, Linux Mint, Arch Linux, OpenSUSE, etc, you can find more at distrowatch
Unix, Linux, windows and compilers etc.
/etc/passwd
/etc/lilo.conf
Use the cron jobs See /etc/cron.daily /etc/cron.weekly /etc/cron.hourly /etc/crontab and the command crontab
There is none. All major Linux certifications (LPI, CompTIA, RHCE, etc...) all cost money.
/etc/apache2
/etc/passwd
/etc/passwd