What is the difference between Bluetooth and Wi-Fi devices?

Bluetooth uses a 2.4 GHz radio frequency band, whereas-Wi-Fi can use 2.4 GHz or 5 GHz frequency band.

Bluetooth is used for Wireless Local Area Networks WLAN only, whereas Wi-Fi is used for Wireless Wide Area Networks WWAN only.

When information is transmitted between two devices using Blue-tooth technology, the devices have to be in the line of sight of each other, but when Wi-Fi technology is used the devices need not be in the line of sight of each other

The statements a and b given above are correct in this context