How does a 2-bit Adder work, and how can i create a 3-bit Adder?

Using Simulink I have been working out the truth table from a 2-bit Adder, and finding out what its purpose is. However I cant explain how it works, so if anyone could right me a relatively easy to understand paragraph or 2 on how it works I would be very grateful!!! Also, I need to write down how to create a 3-bit Adder, but im not sure how to word that either, so if someone could also help with that!!! Thanks.

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).