It is important to remember one key philosophy in Terran vs Zerg (TvZ): Don't let the infestation spread. Terrans have the advantage in the early and especially in the mid game and they have to use it. Advanced hive tech allows the zerg to easily match terran late-game strength. If zerg are allowed to survive with a functioning economy into the late game, a terran base will be overwhelmed with hordes of upgraded units, and any defensive line, no matter how massive, will eventually be broken. We'll start with the least micro intensive tactic that everyone can use with maniacal joy: