Introducing the Terrans

The Terrans are a very flexible race.
With their ability to lift buildings up, you can easily switch the building expansions like the Tech Lab with another building or build your expansion in your safe base, then lift it up with SCVs in it and land everywhere you want to put your expansion.
You can either play very defensive or offensive. Using bunkers and Siege Tanks supported by rocket towers is a very safe way to defend your base. On the other hand, the offensive Terran gameplay consists of fast attacks and hit-and-run tactics. Terran is the only race which has only ranged units.
Unless the other two races, as a Terran you can build wherever you want and you are not restricted to Creep and Pylons.

The Terran army can be divided into the “bio-army“ and the “mech-army“.
In the bio-army you got the reapers, which are perfect for harrassment and scouting, but get a little bit useless later in the game.
Marines and Marauders together with Medivacs are a perfect combination, because you can use the stimpack ability which will boost the Marines and Marauders but also inflict damage on them, which then can be healed with the Medivacs.
The last unit of the bio-army is the Ghost, who is the ground caster-unit of the Terrans. With their EMP you can destroy a units energy, which is very effective against the Protoss since it will destroy their shields.

Besides the above mentioned Siege Tanks and Medivacs, another unit of the mech-army is the banshee.
The banshee has a very good cloaking ability which allows you to easily harrass your opponent and kill his workers. This can also be done with the Viking, which is a strong anti-air unit, but can also be transformed into a ground unit, which can be used to fly into your opponents base, transform it and then harrass him.
The second caster-unit is the Raven, which can’t attack but create towers for energy, detect hidden units and create defense drones to absorb attacks.
The helion is the fastest unit of the Terrans and is good for scouting and harrassment, but not good for longer fights since it dies too quickly.
The biggest Terran unit is the Thor, which costs quite a bit but is deadly against ground as well as flying units, and has also a very good ability to destroy buildings.