What exactly are 'crackers'

You've seen the movies.
The 13 year old nerds who hack into banks, websites, etc, but can an early teen really do so much? Not only that, but how do they know how? Its not exactly rocket science, but its not posted on the net.

I know what they do, but how?
It really facinated me, and I simply want to know more about them

(not asking for a fucking guide here, but im sure you guys get the idea)

>>1
crackers are specifically people who create warez(pirated software) by cracking copy protection or DRM.
hackers hack into computer systems,or any type of software without the motive of distribution of its contents.
Script kiddies (the 13 year olds) download ready made exploits from internet and try to hack with them(without much understanding of their function:like something from movies).
 If they learn the functionality,they move toward becoming hackers.
Hackers can program their own tools and exploits which they use to “leverage their core skillsets” vs exploited software. 
Its not uncommon for hackers to use others tools,or code: hackers don't care about “copyright” or “patents”. 


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The trouble with the rat race is that even if you win, you're still a rat.