Radio, wireless or WiFi?
Wireless: device or communication system that does not include the use of wires / cables. Literally it does not mean that there is a radio transmission or that there is a radio antenna even if today it is used to define the radio transmission. Technically the SterilDisk, for example, is "wireless" because it works without cables and is self-powered even if by now, when we speak of "wireless" it is intnde with radio transmission therefore it is a term that we will not use for non-radio systems.
Radio: any type of transmission that uses radio waves of any type and, therefore, of any protocol (the protocol is a specific method of radio communication).
WiFi: it is a type of radio communication but does not mean "wireless" and does not even indicate any type of radio transmission. It is identified by a precise protocol and defined transmission frequencies.