Ham radio (or more properly amateur radio) involves transmitting. In order to do so legally, you need to obtain a license and a unique call sign from your local government. By international agreement, there are standards which must be met, so there are exams.
If you're just listening, then you're 'scanning'.
The cheap Baofengs are transmitters that cover the VHF and UHF ham radio bands. That's what they were designed for. As nd5y points out, for scanning, they aren't a good choice. The only reason they are so popular for scanning is that they're so inexpensive.
I'd go for the dongle..