Ham radio is another name for amateur radio. To be considered ham radio, the government issues a license and a call sign to whoever passes the examination. CB, on the other hand, stands for citizens band radio. CB is a public radio and an easy way of communication. CB is not as controlled by the government, and you do not need a license for it.
A key difference between the two is that CB equipment can legally broadcast at power levels of up to 1.5 KW. Ham, on the other hand, can be broadcasted worldwide. CB may only transmit for a couple of miles.
Ham radio operators also have a much broader choice of frequency bands, and ham can be used for almost any application, including television, microwave, satellite communication, and even high-speed data access. CB radio users are prohibited from building and repairing their equipment.