Mocha beforeEach vs before execution

While this answer just shows the documentation notes again, and had some comments to try to help show the difference, the answer below by @tomasz-wszelaki should be refered to.

Mocha’s test runner explains this functionality the best in the Hooks section of the Mocha Test Runner.

From the Hooks section:

describe('hooks', function() {

    before(function() {
        // runs before all tests in this file regardless where this line is defined.
    });

    after(function() {
        // runs after all tests in this file
    });

    beforeEach(function() {
        // runs before each test in this block
    });

    afterEach(function() {
        // runs after each test in this block
    });

    // test cases
});

You can nest these routines within other describe blocks which can also have before/beforeEach routines.