Ethernet cables join computers to the local network. Each end has an Rj45 clip. It is useful to know how to make your own so you can decide on a length to suit your need.
Here is a presentation on a method for standard wiring of a cable: (Yes we need better photos : )
Practice Wiring and Ethernet Cable and testing the result
Instructional presentation
Create a presentation in Google Slides or MS-PowerPoint explaining/demonstrating how to do something at which you are skilled.