The so called Quds force is a myth , there's no such thing , there were only some leather jacket brats who exploited the chaos of the 80s and the iranian revolution, and did a couple of assasinations in europe , but that's it , Today there's only the regular iranian army and the IRGC both of which have their elite forces , like every other army in the world
The 80s political assassinations were mostly done by SAVAMA, and as a matter of fact Quds force exists and its commander is Major General Qasem Soleimani it is just not a special force, it is compromised of military advisers, Arabic speaking members and etc, it is mostly like CIA foreign operation apparatus. Quds force is a part of IRGC.
What is the difference between "Regular Iranian Army" and "IRGC" ?
As members said Iran has two Armies.
Iran has an organization named ''
General Headquarters of Armed Forces'' which is the highest military command in Iran, it is headed by General Firouzabadi.
while
Ministry of Defense and Logistics provides weapons and logistics
HQ of the Armed forces commands the forces bellow.
1-Regular Army(Artesh)
2-IRGC(Sepah Pasdaran)
3-Law enforcement Forces(Iranian police)
Regular Army(Artesh)
Regular Army itself has four services:
1-Ground force(IRIGF): It is a heavier force(more tanks, artillery) than IRGC-GF, it also Has SRBMs
2-Air force(IRIAF): Controls all of Iran's fighter and bomber fleet, also have UAVs
3-Navy(IRIN): Controls Iran's heavier Ships and also controls all of Iran's Subs, has two marine brigades
4-Air Defense Command(IRIADF) aka Khatam al anbia base
Regular Army as its name indicates is like an ordinary Army charge with defending Iran, it is mostly a conventional force.
IRGC(Sepah Pasdaran)
IRGC has five services
1-Ground forces(IRGC-GF): It is lightly manned in peace time and is heavily integrated in Resistance force.
2-Aerospace Force(IRGC-AF): It controls most of Iran's SRBM and all of MRBMs, it also has Su-25 and UAVs
3-Navy(IRGC Navy): Based in Persian gulf, mostly armed with speed boats and anti ship missile batteries, has marine brigades
4-IRGC resistance force(Basij): it is mostly a reserve force(in war most of IRGC division will be manned by Imam Hussein battalions), has Imam hussein(millitary), Iman ali(Securoty), Bei ol moqadas(Rapid defense force) and kowsar(female) Battalions.
5-Quds force: External operation force
IRGC has other independent organization like Ansar al mehdi corps(VIP securty), vali amr corps(Leader securty), air security corps and khatam al anbia construction base
IRGC is mostly a asymmetrical force, it is also charged with defending the revolution.
The IRGC has overgrown in the past 20 years to actually be the de facto ruler in Iran. Many observers go as far as saying that even Ahmadinejad was just a mask used by the IRGC to facilitate putting their hands on the post 2005 huge oil revenues. To complete the joke, they represented Ahmadinejad as a very honest politician who owns 1977 old car! All in the middle of looting zillions of petro dollars, and dragging Iran into useless external conflicts. No wonder why his presidency was completely disastrous.
The IRGC's size and power are so immense now that the Supreme Leader can no longer control effectively. However, I must say that they are credited for fighting brutally in Iraq - Iran war, particularly for pushing back the Iraqi troops to the Iraqi boarders. It appears that the Mullahs themselves are not interested in improving the Iranian army's capabilities, and want to always make sure that the IRGC will prevail over the army in case of any possible conflict between the two.
IRGC is completely under Supreme leader controls and loyal to him(leader have representatives in IRGC and can easily change and appoints IRGC commanders) , all of those observers(like Alfoneh and etc) mostly publish BS, IRGC is a military organization, yes many IRGC veteran have entered politics but IRGC is still subordinate to Armed forces command.
As a matter of fact Army has a larger budget than IRGC but IRGC has some economical activities and has fewer standing(not reserve) personnel
IRGC and Army have two different strategy so they receive different kind of weaponry , for example IRGC AF receives our ballistic missiles while army navy will receive the newly built subs and frigates, IRGC Navy receives speed boats