Angular HttpPromise: difference between `success`/`error` methods and `then`'s arguments

Question

According to AngularJS doc, calls to $http return the following:

Returns a promise object with the standard then

Answer 1

Some code examples for simple GET request. Maybe this helps understanding the difference. Using then:

$http.get('/someURL').then(function(response) {
    var data = response.data,
        status = response.status,
        header = response.header,
        config = response.config;
    // success handler
}, function(response) {
    var data = response.data,
        status = response.status,
        header = response.header,
        config = response.config;
    // error handler
});

Using success/error:

$http.get('/someURL').success(function(data, status, header, config) {
    // success handler
}).error(function(data, status, header, config) {
    // error handler
});