This is a common term used to mean radio transmission. Although there are no wires in Infra Red, it is not what people generally mean when they say wireless.
Building a robot with wireless communications system may mean they are able to communicate and download new programs fairly easy.
In fact, early robots - like Shakey, were connected to huge computers via a radio link.
These are however susceptible to interference- and without encoding - interception or corruption. While these would present great troubles to a home grown or raw protocol, Bluetooth and WiFi deal with such problems fairly well.
Beware - noisy motors without suppressor caps may seriously degrade signal quality (and therefore range and download speed) quite significantly. If you are intending to sell any robot - you must consider the various RF laws and recommendations. Many bandwidths are pre-allocated, so using the hobbyist 27mhz band is recommended.