A network telescope is like a big telescope that looks at the entire sky instead of just one star or planet. It looks at the sky to try and find things that are not supposed to be there, like bad guys trying to do bad things.
Instead of using lenses like a regular telescope, a network telescope uses computers to collect information from the internet, which is like a big network of computers all connected together. The network telescope can see if someone is trying to break into a computer or if a computer is trying to attack other computers.
Like a real telescope, the network telescope doesn't just look at one thing, it watches a lot of things at once. That way it can catch bad guys doing bad things in many different places all at once. This helps keep the internet safe for everyone to use.