We often encounter people in airports, libraries, restaurants, etc. using electronic devices, such as notebooks , to access the internet without using cables for connection.
The so-called Wi-Fi network is a wireless network (also called wireless ) in which we can access the internet only by radio waves, as well as televisions and cell phones, without the need for connecting wires.
Radio waves are electromagnetic waves (formed by the combination of the electric and magnetic fields that propagate in space perpendicularly carrying energy) used by radio stations.
Basically, in places where there are systems that use radio waves, an electrical circuit is responsible for causing the electron oscillation in the emitting antenna. These electrons are accelerated and, as a result, emit radio waves, which carry the information to a receiving antenna.
Wi-Fi networks, used to provide wireless internet access, operate in a similar way: an adapter (wireless) for computers captures information and translates it into the form of radio signals, which are transmitted with the aid of a antenna.
The router (also wireless), whose function is to distribute the network signals, in addition to “choosing” the best way to send a set of data, is the one who receives the signal and decodes it. It is he who sends the information to the internet using a (wired) connection, Ethernet, responsible for the interconnection of local networks.
It is worth noting that the reverse process can also occur: the router can receive information from the internet, translate it into radio signals and send it to the adapter.