In the American submarine force their are two types of missiles:
1. Tomahawk® Land Attack Missile (TLAM)
2. Sea-launched ballistic missile (SLBM)
A multiple independently targetable reentry vehicle (MIRV) warhead is what is deployed on a SLBM. The TLAM can carry a conventional warhead or a single nuclear warhead.
Torpedo
Trident Ballistic Missile Submarine
A torpedo...
The codes are- for conventional () non nuclear powered) Submarines- SS ( for example the U.S.S. is SS-297. Atomic subs are SSN or SSBn - BN if fitted for Ballistic missiles such as the Polaris or Trident types ( there is no Submarine Called the Polaris- it is a guided missile!) so SS- submarine, SSN- Nuclear submarine- SSBN- Nuclear submarine- Missile type.
Royal Navy submarine
No
The Russian missile launching submarine, Typhoon Class, is slightly bigger than the USA missile launching submarine, Trident Class.
EDGE information technology
Torpedo
It's a submarine-launched ballistic missile system comprised of the Trident missile, the special Trident warheads and the Ohio-class ballistic missile sub.
The modern definition of a torpedo is a self-propelled underwater missile. (see related question)
USS George Washinton.