Your Mac can function as a wireless hotspot, allowing you to connect your other devices to it and share its Internet connection. It’s just like tethering to your phone.
This is most useful if your Mac is connected to a wired network interface via Ethernet. You can connect your wireless devices to your Mac and share the wired Internet connection with them.
Enable Internet Sharing and Configure Your Hotspot
The Wi-Fi hotspot option is part of the “Internet Sharing” feature in Mac OS X. You’ll find it in the System Preferences window.