Eh... less of a 101 then this is how you learn starcraft 2 from someone that doesn't know how to play starcraft or starcraft 2. Terran is probably the most defensive race due to their frail yet high damaging units. So you need to get into a good position or you will get routed. And since everyone of their units can have their health restored in one way or another (repair/heal) they can recover faster from an attack more so then any other race.
The biggest thing you missed when talking about terrans is walling off. Since marines are the weakest starting unit (for equal minerals spent, they will lose to both zerglings and zealots). A wall is necessary to keep out the first few pressuring units (since both other races starting units are melee, they can't attack the marines blocked off). And since supply depots can lower them selves, they make the perfect wall and door to your base entrance. Unless you like the idea of zerglings or zealots raping your scvs in the first 2 mins of the game.
MurderousToaster said:
Can I ask if it's possible to zerg rush in this new Starcraft game?
[sub]kekekekeke[/sub]
Yes. Yes you can. Cheese is not only exclusive to the zerg btw. Bunker rushing is now easier to do due to auto repair, scvs attack moving correctly, and bunker salvage makes it a much deadlier strat. And chrono boost makes pumping out zealots from proxy gates much much faster.