There may be times when you find it necessary to share your internet connection with other users on your local network. If so, do this in macOS:
1) Open sharing settings if it is not already open (choose Apple menu> System Preferences, then click Sharing).
2) Check Internet Sharing.
3) Click “Share your connection from” pop-up menu, then select the Internet connection you want to share. For example, if you are connected to the Internet via Ethernet, select Ethernet.
4) Select how you want to share your Internet connection in the “To computers that use:” list. For example, to share your Internet connection over Wi-Fi, select Wi-Fi.
If you share your Internet connection over Wi-Fi, clear the Internet sharing check box, click Wi-Fi options, give your network a name and password, and then select the Internet sharing check box.
Note that if your Internet connection and local area network use the same port (for example, Ethernet), you should check for possible side effects before turning on Internet sharing. In some cases, sharing your Internet connection interferes with the network. For example, if you use a cable modem, you may inadvertently affect the network settings of other ISP clients, and your ISP may terminate your service.