MOOCs

 MOOC stands for massive online open course.
There are several websites offering MOOCs for free of charge.
www.coursera.org
www.edx.org

How MOOCs are different from online courses? I need to explore..

here is the post by janet Webster which explains it clearly
https://class.coursera.org/massiveteaching-001/forum/thread?thread_id=126
I have a lot of experience teaching online courses at my university using Moodle LMS (free open software) and more recently (past 2 years), I have been involved in the open education movement by taking and co-facilitating Moocs.
Let me try and answer your question (I probably need cutouts....)

 The boundaries are fluid with all of these categories.

•  For example, I teach online courses, but students are required to attend campus for their final exams. The scheduled campus meetups (if any) are at the discretion of each professor. The courses are marketed to students as 'online', but in reality they still require f2f contact.
• A regularly scheduled blend of f2f and online are these days called 'blended mode' courses. Again, the professor determines the 'blend' and of course there is a lot of experimentation involved-what works and what does not.
•  Other institutions (not mine) offer distance education (old term)  or online (current term) where all course requirements are met on whatever online platform has been adopted by the institution (Moodle, D2L, Canvas and others)
• You can now accomplish undergrad and even graduate designations completely online through a program of studies offered by many institutions by taking all of your courses online. Generally, the curriculum is determined by the prof for each course
• These kind of online courses are not open; you pay for the course and get  password protected access to the online course. There is a limit to the registration.

Year 2008 and along comes the Mooc- a term coined by Canadian Dave Cormier: here is Dave Cormier's You Tube video 'What is a Mooc?'

The original concept of a Mooc is that of a networked learning environment that is open on the internet (free access to knowledge, teaching / learning). The important principle of the Mooc as it was conceived by Stephen Downes is that of a network of learners-sharing resources and participating in the knowledge - building. Creative Commons licensing is very much in the spirit of the connectivist Mooc as originally conceived.
here are many educators running really open Moocs on the internet using freely available online platforms such as WordPress, Google, Twitter. Check out University of Mary Washington's (Md) Digital Storytelling 106- courses are run on campus, but are also completely open to anyone with an internet connection. Many courses and programs have played around with certain characteristics of the Mooc and discovered new ways of offering material on the internet.Debbie Morrison has a good blog here about xMoocs and cMoocs.