You have many different kinds of hacks like:

DOS, DDOS, PDOS, Phising, Social engineering, Keyloggers, Waterhole attacks, Trojans virus, Worm virus, etc.. there are many more but if i wanted to say all i'd be writing for years and not even be done.. 

Let's talk about the hack you can do right now; Social engineering

 

 

Social engineering is the easiest way of hacking, it's using the weakest thing in your whole security....     YOU.  

 

Why are you the weakest thing in your own security? because you're a human and humans have a way of thinking, your brains try to use the easiest way to do things. here is an example of social engineering:

 

(try to think your on a tv show)

TV host: Ok, so what kind of password do you have Amy?

 Amy: my name and my date of birth.

 TV Host: and how old are you?

Amy: 14 years old

TV Host: so you were born in 2002?

Amy: no i was born in 25 november 2003

TV Host: so your password is Amy251103?

Amy: ...........

 

See how in the example the TV Host got the password?

usually it's not that easy and you have to guess a few more times but it's the easiest way of getting a password.