What is Wi Fi technology and over which main frequency bands does it usually operate in wireless local area networks?

Introduction / Context:
Wi Fi is the common name for a family of wireless networking technologies that allow devices to communicate over short ranges without cables. It has replaced many wired local area network connections in homes, offices, and public spaces. This question asks you to define Wi Fi technology and identify the main frequency bands in which it operates.

Given Data / Assumptions:
- Wi Fi is used for local connectivity between devices and access points.
- It is standardized under IEEE 802.11 specifications.
- Wi Fi operates in license free industrial, scientific, and medical ISM bands.
- Users typically encounter 2-4 GHz and 5 GHz Wi Fi networks on consumer routers.

Concept / Approach:
Wi Fi is not a cellular or satellite technology, but a wireless local area network technology. It uses radio waves in unlicensed bands so that consumer equipment can be deployed without individual spectrum licenses. Most common standards such as 802.11b, 802.11g, and 802.11n use 2-4 GHz, while 802.11a, 802.11n dual band, 802.11ac, and later standards use 5 GHz bands. The correct option should mention IEEE 802.11 and these bands rather than unrelated frequencies.

Step-by-Step Solution:
Step 1: Recall that Wi Fi is defined by IEEE 802.11 standards. Step 2: Identify the typical bands: 2-4 GHz for older and longer range networks, and 5 GHz for higher throughput networks. Step 3: Compare options and pick the one that states Wi Fi is a wireless LAN technology using these unlicensed bands. Step 4: Confirm that the chosen option does not confuse Wi Fi with wired Ethernet, cellular, or satellite standards.

Verification / Alternative check:
Router specifications and Wi Fi equipment datasheets list supported frequency bands, normally 2-4 GHz, 5 GHz, or both. Tools that scan Wi Fi networks can show which band a given SSID uses. Standards documents for IEEE 802.11 also describe operation in these ISM bands. This evidence supports the selected description.

Why Other Options Are Wrong:
Option B is wrong because Wi Fi is wireless and does not use copper cables as the transport medium, and 60 Hz is related to power lines, not data transmission. Option C is incorrect since satellite communication uses different standards and higher frequencies than typical Wi Fi, and is not called Wi Fi. Option D confuses Wi Fi with cellular voice protocols that run on licensed spectrum such as 900 MHz and 1800 MHz.

Common Pitfalls:
A common mistake is to assume that all wireless internet is Wi Fi, even when it is cellular data such as 4G or 5G. Another pitfall is ignoring differences between 2-4 GHz and 5 GHz in terms of range, interference, and speed. Understanding Wi Fi fundamentals helps users choose correct equipment and channels and distinguish Wi Fi from other wireless technologies.

Final Answer:
Wi Fi is a wireless local area networking technology based on IEEE 802.11, and it usually operates in unlicensed 2-4 GHz and 5 GHz radio frequency bands.