ok. The answer to your questions are contained in a weeklong course in Tampa, a series of books, or those who have been attached to a SOF unit.
Special Operations Forces (SOF)
Air Force -
160th “Night Stalker” Special Operation Aviation Regiment - 'special' pilots with 'special' aircraft to fly SOF operators around the world. They also train medics to HALO jump into a fight to provide EMT and life saving measures
Navy -
SEALs - maritime special operations. They specialize in direct action, special reconnaissance, and underwater unconventional warfare and can infiltrate and operate from the sea, air, and land.
Army- 75th Ranger Regiment - specialize in combat missions that involve insertion of relatively large units into hostile territory
- Army Special Forces (Green Berets) - specialize recruiting, organizing and training local forces; and accompanying or leading them in combat operations supporting U.S. objectives
- Special Forces Operational Detachment D (Delta Force) - focuses on direction action counter-terrorist missions such as hostage rescue and capture or killing of high value targets, as well as protection of high-ranking individuals
"Varsity Level" SOF (Tier 1 units) -
Delta Force - https://nationalinterest.org/blog/buzz/secret-now-out-how-delta-force-was-born-62282
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DEVGRU (SEAL Team 6) - https://nationalinterest.org/blog/buzz/what-makes-seal-team-6-so-dangerous-213825
- Ranger Regimental Reconnaissance Company
- Intelligence Support Activity
- 24th Special Tactics Squadron
That said, here is an article that breaks it all down for you in just a few minutes worth of reading: https://nationalinterest.org/blog/reboot/confused-all-us-special-forces-heres-guide-192216
