Sharing the Internet is a function included in your iPhone that allows you to share the mobile data of your iOS terminal. When activated, it creates a Wi-Fi network from which other Wi-Fi devices can be connected to the Internet, such as laptops, tablets, Smart TVs, Chromecast or other mobile devices.
How to share the mobile data of your iPhone
First, go to Settings > Cellular and Activate Cellular Data.
Then go to Settings > Personal Hotspot and Activate Personal Hotspot.
To protect access to the Wi-Fi network that has been created, you can set a password. Touch Wi-Fi Password, enter a password and press OK.
To connect a laptop to the Internet, click on the wifi icon, select the network created by your iPhone and enter the password.