Moodle Development - Get course(s) using Moodle's Data Manipulation API

To get course(s) using Moodle's Data Manipulation API, from version 2.5.1 we can do like following:

* Get a specific course with provided id:

$course_id = 20
$course = get_course($course_id);

(instead of :

$course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);

)

* Get all courses in the system:

$courses = get_courses();