А как можно купить USB (Universal Serial Bus standard)?

That’s what we call a charger/connector that has a USB head.

Трудно поверить.
USB charger, USB cable, USB port, USB adaptor, USB power supply, USB power bank, USB card reader, ...

Grumbler, those are the full and correct names, but in everyday life, we say we’re going to buy a USB.

It’s short for a USB cable.

Не знаю про Америку, но, думаю, не в России (и рядом с ней).
Можно тольк догадываться, что именно Hanna имела в виду, хотя не исключено и что именно зарядное устройство.

Well, if she bought a bag for her laptop, chances are that she bought a cable to charge it with. Otherwise it’s anyone’s guess, and, as luck would have it, USB sounds fine on its own in English.

Сhances - yes, but most (all?) laptops have a special port and a cable for charging that aren't USB.

But sometimes you need a USB to connect your devices.

yes