"Wi-Fi" is a type of wireless networking protocol that allows devices to communicate without cords or cables. Wi-Fi is technically an industry term that represents a type of wireless local area network (LAN) protocol based on the 802.11 IEEE network standard. It's the most popular means of communicating data wirelessly, within a fixed location, today.
"Wi-Fi" is a trademark of the Wi-Fi Alliance, an international association of companies involved with wireless LAN technologies and products.
Wi-fi is commonly mistaken as an acronymn for "wireless fidelity" and often you may also see it spelled without the hyphen (wifi).