Ground Forces

While not as commonly used today as in previous times, the Federation does still maintain ground forces, in the form of Military Assault Command Organization, or MACO.   Starfleet also has a few special forces groups operating under various names, but MACO does make up the majority of the high-performance combat groups.
Ground Forces are specifically tasked with ground-based security and combat, and are trained on a variety of weapon systems and platforms tailored for that arena.   As such, most Ground Forces can be expected to fight with anything from a simple knife to a sniper rifle as necessary, though individual soldiers may have specialties in one area or another.   Some of these specialties are as follows:
===Close-Combat Specialist===
The close-combat specialist, also known as the Close-Quarters Combat (CQC) specialist, is specifically trained in combat techniques useful in tight quarters.  These techniques often include martial arts, but may also include varying forms of small-arms such as pistols and shotguns.   CQC specialists are also trained in melee weapons ranging from knives to swords and staves.  These operatives are experts in neutralizing opponents in close proximity, whether it be a single opponent or a group. CQC specialists may operate alone, but typically operate with a full squad.
===Demolitions Specialist===
Demolitions specialists are experts in the setup and use of multiple forms of explosives.   These specialists are often used as Explosive Ordinance Disposal (EOD) Technicians, but tend to prefer setting up to tearing down.   While all Demolition Specialists are trained in the standard ordinances in use by the various departments of the Federation, ranging from photonic to quantum and antimatter, most have their own preferences for various needs and uses.  Demolitions Specialists typically operate in conjunction with a full squad.
===Long-Range Marksman===
The Long-Range Marksman, also refered to as a Sniper, is an especially accurate marksman often used specifically for high-value targets.  While the Federation and Starfleet abhor the death of intelligent beings, it has at times been necessary when all other options have failed.   The Sniper excels at a stealthy approach and operation, and is often completely undetected from start to finish.   While all Snipers are trained on the various firearms in use by the Federation, most have chosen or created their own weapon specific to their own preferences.     Snipers typically operate in teams of two, consisting of the Sniper and a Spotter.
===Infiltration Specialist===
The Infiltration Specialist, sometimes referred to as the Ghost, is an especially stealthy member of the team.   These specialists are masters of the silent approach or disguise.   They are often tasked with entering a hostile environment in order to prepare either the team or the target.  Ghosts have occasionally been tasked with infiltrating a high-priority target's security team, or even rescuing a hostage.   These operatives almost always operate alone, or in coordination with other Ghosts.