The groups share a similar ideology. But there are key differences.
MORE: http://www.cnn.com/2014/09/24/world/meast/isis-al-nusra-khorasan-difference/index.html
See also...
The anatomy of ISIS: How the 'Islamic State' is run, from oil to beheadings
http://www.cnn.com/2014/09/18/world/meast/isis-syria-iraq-hierarchy/index.html
200,000 flee in biggest displacement of Syrian conflict, monitor says
http://www.cnn.com/2014/09/22/world/meast/syria-civil-war/index.html
Teen who escaped ISIS: 'My friends were raped'
http://www.cnn.com/2014/09/23/world/meast/coren-isis-khanke-refugee/index.html
Syria crisis: At least 200 killed in one day, group says
http://www.cnn.com/2014/09/17/world/meast/syria-crisis/index.html
Yet another beheading. What's the world going to do about ISIS?
http://www.cnn.com/2014/09/15/world/meast/isis-threat/index.html
How foreign fighters are swelling ISIS ranks in startling numbers
http://www.cnn.com/2014/09/12/world/meast/isis-numbers/index.html
ISIS video shows beheading of American journalist Steven Sotloff
http://www.cnn.com/2014/09/02/world/meast/isis-american-journalist-sotloff/index.html
Double suicide bombing kills at least 9 in ISIS-besieged Iraq town
http://www.cnn.com/2014/09/08/world/meast/iraq-town-suicide-bomb-attacks/index.html
Report: ISIS waterboarded captives
http://www.cnn.com/2014/08/29/world/meast/isis-waterboarding/index.html
