Okay kiddo, so imagine that Tuvalu is like a big treehouse club where all the grown-ups get together and make decisions about how their club works. Just like in a treehouse club, sometimes the grown-ups have to talk about really important things like rules and how the club should change.
In 2008, the grown-ups in Tuvalu had a really big talk about their club's most important rule book called the "constitution." They wanted to make some changes to the constitution but they didn't want to just do it without asking everyone else first.
So they did something called a "referendum" which is basically like taking a vote. Each grown-up in Tuvalu got to decide whether they agreed or disagreed with the changes to the constitution.
This was a really important decision because the constitution is what helps the grown-ups in Tuvalu make decisions about how to run their country. And just like in a treehouse club, sometimes the grown-ups need to make changes so that everything works better.
In the end, enough grown-ups in Tuvalu voted in favor of the changes, so they made the changes to the constitution. This is how democracy works - everyone gets to have a say in important decisions that affect their country.