Spacers and standoffs are small but important components that, when used in certain installations and applications, allow for more precise positioning of screws, fasteners and other parts.
Spacers and standoffs can be crucial in achieving both improved aesthetics and proper functioning of certain devices and products, including avoiding short-circuiting of powered components (such as computer motherboards) by creating a small air gap between the powered component and any metal housing it's installed into.
A spacer is a small piece of material - generally metal or plastic - that sits under the head of a screw or bolt but on top of the surface being screwed into, rather like a more elongated version of a standard washer.
A standoff is a similar component to a spacer in many ways, with the key difference being that standoffs tend to be threaded onto the screw and/or the surface they're being installed on.
A swaged standoff is one that has both internal and external threading cut with a swage tool, creating an end which resembles a male exterior but that retains internal (female) threading, allowing for tighter grip on both male and female fasteners and anchor points.