Plunderphonics is when a person takes little pieces of different songs and combines them together to make a brand new song. Have you ever played with Legos and built a new toy by putting together pieces from different sets? That's kind of what plunderphonics is like, but with songs instead of Legos.
For example, a person might take a beat from one song and mix it with a melody from another song. They could then add in some lyrics from yet another song to make a completely new composition that is made up of snippets from other songs. This new creation is called a "plunderphonic" piece of music.
Some people think that plunderphonics is really cool because it allows artists to create unique sounds and music that can't be made any other way. Others think it's not very creative because they're just taking bits and pieces from other people's work.
Either way, it's important to remember that whenever you make something new, you should always give credit to the original creators. That way, everyone gets recognized for their hard work and talent.