Mobile two-way radios are primarily designed for use in a vehicle. They have a bracket that enables you to mount them under your dashboard or in some other convenient location, plus they run off the 12 volt vehicle battery power. You could also use these radios inside a building as long as you use an AC to DC converter to provide the 12 volts DC they need.
The benefit of these radios is their power output. They may have as much as 100 watts of power, but are more likely to have under 50 watts.
There is no built in antenna so an external antenna is required. Given the high power nature of these radios, the antenna should be outside the vehicle or building and mounted as high as possible and the cable of the antenna is then run the connector on the radio.