Can I update an iPod touch to 16?

I really don’t understand how to update my iPod touch to the 16 (version?) I tried asking Siri, and searching the web. I also went into Settings > General > Software Update > Automatic Updates, but then then it opened to two things—Download iOS Updates and Install iOS Updates. Then it said that my iPod touch is up to date—15.8.3

Please someone tell me how this works.