What does it mean?
Where power is maintained by the people and representatives. People vote the representatives they want or if they want to change the representatives they have now. different representatives have different powers.
What is it like?
It's like the US, where we have different representatives. Some representatives we have are a president, a house of representatives, a senate, etc.
What is it NOT like?
It is unlike a Monarchy, where the country is ruled by a king and queen, or a royal family.
In the next year, the US will vote on who they want to become president. We can do this because we are a republican government. We wouldn't be able to do this if we were in other place such as North Korea, England, etc.