What are the differences between 'nicht' and 'kein'? How to use them in sentences?

Question

Answer

"KEIN" is a negative article, which u use only with nouns - 
Ich bin ein Student (I am a student)
Ich bin kein Student (I am not a student)

"NICHT" is a more global negation, which, actually, can deny anything (verbs, adjectives, ...)  - 
Ich mag dich nicht (I don´t like you).
Das Kleid ist nicht schön (The dress is not beautiful)

Answer

kein = nicht ein

That sums it up really.