Cold card supports the newly implemented partially signed transactions, meaning you can create a tx on the computer, put it on an SD card, insert the car into the cold card and sign the tx, then put it back in the computer and broadcast. The device never touches the internet
A USB "condom" is a piece of middleware hardware that connects your device to your computer's USB in order to protect it against USB firmware attacks. Coldpower is used to power your coldcard via USB. The functionality is entirely and completely different. Even the specific purposes are completely different.
Because putting a battery in the cold card would have been just too simple, we have to have one of those horrible fiddly mUSB ports connecting to this piece of shit without the connection coming loose
edit: I'm not buying until they make USB-C version. I vow never to use mUSB again in my life, I hate it with a passion. Every mUSB device I own has connection issues, especially XBOX controllers. Horrible.