what does \ do in a command?
 

You know how when you at the cli, and you type in a command and hit enter? well sometimes I hit the \ key as well as enter and it drops down to another line that starts with a ?. What is the function of that?

You use the backslash-enter key sequence to tell the shell you are giving it a multi-line command. The line starting with the question mark is just the shell's way of saying "Ok, gotcha... you need another line. Here's a very simple prompt so you can continue."

backslash is a special key, its use means take the next key as its ascii value, NOT its assigned function..

for example. in C++.. here is a hello world program.

cout << "Hello World";

but what if you wanted cout to print the character [ " ]

cout << " She said "You Smell !" ";
COMPILE error. !!!!

so you would use

cout << " She said \"You Smell !\" ";

the same thing is used to put spaces in file names (in command line)

Ahh i gotcha thanks. :)