Johan Richter was a person who created new things that people could use. Think of him like your favorite toy maker, but instead of toys, he made inventions for grown-ups. He probably looked around and saw things that could be better or easier, and he worked on ways to make that happen. It's like when you see a puzzle with missing pieces, you start thinking of ways to complete it.
Some of Johan Richter's inventions may have been things you use every day, like a phone or a computer. Other things may not be what you're familiar with, like machines that help people do their jobs better or faster. His inventions might have helped people create new medicines or build bigger buildings. He was a very smart person who spent a lot of time thinking and figuring out ways to make the world better for everybody.