Okay, so you know how lighthouses are tall towers with lights on top that shine out to help boats and ships know where they are and not crash into rocks or other dangerous things in the water?
Well, lighthouse tenders are special boats that help take care of those lighthouses. They bring supplies like food and fuel to the people who work at the lighthouse and make sure everything is working properly.
Just like you need to take care of your toys, the people who take care of the lighthouse need to make sure the light bulbs are working and the lenses are clean to make sure the light shines bright and helps the boats stay safe.
The lighthouse tender also helps make sure the lighthouse is painted and looks nice, so the boats can easily see it from far away. Think of it like a big boat helper that takes care of the lighthouse and helps make the water safer for everyone.