What is the difference between a generative and a discriminative algorithm?

Question

What is the difference between a generative and a discriminative algorithm?

Answer 1

Imagine your task is to classify a speech to a language.

You can do it by either:

1. learning each language, and then classifying it using the knowledge you just gained

or

2. determining the difference in the linguistic models without learning the languages, and then classifying the speech.

The first one is the generative approach and the second one is the discriminative approach.

Check this reference for more details: http://www.cedar.buffalo.edu/~srihari/CSE574/Discriminative-Generative.pdf.