WiFi is short for "wireless fidelity." Many new computers now come with wireless capability. You can connect to the Internet and other computers without using cables.
Many airports, hotels, coffee shops and other facilities offer public access to WiFi networks so individuals can access the Internet and check their emails while traveling or in between meetings. These locations are called hotspots. Usually, the managers of the facility, e.g. a hotel, will provide you with a login and password so that you can make use of the access. Sometimes, if you are near a "hotspot" you can see a listing of it on your computer's Internet access set up and you can gain access without a password.
There are web pages such as WiFi HotSpot list that provide lists of hotspots in various locations.