Is exchange for free legit?

Hello there, I've come across the concept of 'exchange for free' in the cryptocurrency world and I'm wondering if it's actually legitimate. Can you explain what this means and if there are any risks associated with it? I've heard some people say that it's a great way to get into the market without investing much, but I also want to make sure I'm not falling for a scam. Could you shed some light on this topic for me?