A Turing complete system is a system that can do anything that any other computer can do. Think of it like a robot that can do any task you give it. Just like humans can do a lot of different things, a Turing complete system can do a lot of different things too. It can solve any set of instructions you give it, no matter how complex. To make sure that it works, it needs to use a set of instructions called a computer program. A computer program tells the Turing complete system exactly what to do. So, if you can make a computer program, then the Turing complete system can do whatever you want it to do!