Here in the USA, most consumer power strips seem to make use of NEMA 5-20R connectors – they look something like this. However, in the rackmount/datacenter world, I see a lot of power distribution units that accept IEC C14 connections instead, which look like this.
I know there's no significant difference electrically; I'm wondering why I should prefer one over the other. In my limited experience, I've found that connecting C14 connections to a PDU results in looser connections that I'm more likely to have fall out without securing them with zipties or velcro.
Best Answer
I think it's a question of voltage. NEMA 5-20R can only support 125V (the common household voltage in the US...minus your electric clothes-dryer, of course). IEC C14 can support up to 240V, a more common voltage outside the US.
So why would 240V be better than 125V? The higher the voltage, the more efficient the power supply (I believe because it doesn't have to be stepped down as much from the building's electrical feel...which is 480V (or higher, with even larger buildings).
By way of a real-world example, we've switched one of our DataCenters to be entirely 3-phase 208V power (using IEC C13/14 and C19/20 outlets). We're expecting to lower our bill by almost 50% compared to the 125V power (not accounting for overall growth).