Drill Teams
There are several drill teams that a cadet may join. Not all schools may have every drill team listed. The Drill Teams are: Silent Drill Platoon, Unarmed Drill Platoon, Unarmed Drill Exhibition, and Armed Drill Exhibition. Most competitions also have Armed and Unarmed Drill Downs.

Silent Drill Platoon
The silent drill platoon is just as the name says. The platoon performs a pre-choreographed routine of drill with different rifle tricks. The platoon usually consists of 2 squads of about 10 cadets plus the Drill Commander.
Unarmed Drill Platoon
The unarmed Drill Platoon is usually 2-3 Squads of 6 cadets plus the Drill Commander. All this team is, is the Drill Commander calling out different regular Drill Commands. It is the simplest drill team to join.
Unarmed Drill Exhibition Team
This is what my friends used to call the "Slappy Hand Team." This team consists of either 2 or 4 cadets who choreograph a routine using Drill and different things with their hands. The closest thing this team can be compared to is a strange looking dance routine. For reference you may find an example of this type of drill is the Disney Channel Movie "Cadet Kelly."
Armed Drill Exhibition Team
This team is the most similar to the silent drill platoon. It consists of 2 or 4 cadets on a team the choreograph a drill routine using their rifles and doing more of the more difficult tricks. The Armed Drill Exhibition Team is usually your best Drill cadets mainly because of the difficulty of the routine.
Armed and Unarmed Drill Down
A team of 5 cadets and an alternate is on each team. The drill down commands are basic commands: Unarmed- left face, right face, about face, parade rest, attention, hand salute; Armed- same as Unarmed, present arms, port arms, left shoulder arms, right shoulder arms, order arms, inspection arms. The whole competetion is based on who can do these commands flawlessly, so if you mess up, you're tapped on the shoulder and have to leave the competition.

Colorguard
Colorguard is one of the most honored of all the teams. Not only due the teams have to compete in competitions but they also must perform for ceremonies, District Inspection and are also usually used at the begining of the Schools sports games along with opening the Programs competetitions. Colorguard consists of 4 cadets plus 1 cadet as an alternate. The cadets are: left rifleman, U.S. colors, Marine Corps Colors, Right rifleman, and the alternate who usually is proficient in every position. The cadet carrying the U.S. Colors (flag) is the Colorguard Commander.
 
Rifle Team
The rifle team, or shooting team can consist of as many people who want to join but only 5 members and 1 alternate will be used at competition. The team uses air rifles and shoots in 4 different positions: prone (laying), sitting, kneeling, and standing. It is possible that there is also a pistol team.
Physical Training (P.T.) Team
The PT team has around 20 cadets and depending on the competition is how many cadets will be used. The PT team concentrates on Pull-ups (males), Flex-arm hang (females), crunches, and a 1 mile run.
Mountaineering
Mountainteering consists of cadets learning how to tie safety-lines and set up climbing and rapelling lanes and learning how to climb and rapel. Not every school has this. Note: New Marine Corps regulations prevents JROTC units from practicing this On-Campus and can now only climb/ rapel on certain field Trips. General orienteering can still be taught on school campus.
Other MCJROTC Activities include: Marine Corps District Inspection, Leadership Camp, Shooting Field trips, Scuba, Map Reading, Orienteering, Paintball, Recruitment, Community Service, Summer Camp, and Devil Pups (operated by the United States Marine Coprs).