Just to confuse you a little more, there are different levels of "booting".
A "cold boot" means to switch the computer off for a few minutes, let the electricity stored in the chips bleed off,
and then switch it back on.
A "warm boot" means to leave the computer on and go through a "restart" or "reload" of the operating system.
Hitting the "restart" button on the computer is somewhere in between.
The point of "rebooting" is to reload and reset all of the operating software in your computer.
The operating software includes, but is not limited to the operating system(windows), motherboard BIOS(basic input/output software),
video BIOS, soundcard BIOS, controller card BIOS, modem BIOS, network card BIOS, wireless card drivers, mouse drivers,
printer drivers, video drivers, CD/DVD drivers, network drivers, modem drivers, etc.
All of this junk running around in a computer can occasionally have conflicts and cause problems.