StarCraft/Buildings

Basics
Players have many ways of constructing structures. The fastest method is to use the hotkeys B for Build and V for Advanced Build, then pressing the associated hotkey for a particular structure while hovering the mouse near the prospected building site.

Buildings take a rather short time to build, and are rather cheap compared to units. Therefore players generally build ample buildings. Another reason of doing this is use as backup. If an enemy destroys a Protoss Gateway, for example, the player cannot build Gateway associated units nor travel up the tech tree for about another crucial minute (until a Gateway is rebuilt) UNLESS the player has at least one that was not destroyed.

Building locations are also crucial, as they may determine the ease or difficulty of bypassing units-either moving your units from one front to another or to prevent enemies from simply running past defensive structures. Buildings can be used to protect a Terran Siege Tank in Siege Mode as well as grant it extra range; enemies attacking it would be outside the 'too close' range. Meanwhile, the same buildings could block a Reaver's attack pathway or at least slow down its rate of fire.

Defensive structures should be placed at chokepoints for maximum effectiveness and should be spread out throughout the base-especially at resource nodes-to defend against enemy infiltrations and provide response time for your units.