Have you ever heard someone make a hissing sound like a snake? That's what we call a sibilant. It's a common sound in words that have the letters "s," "sh," "ch," and "z."
When you make a sibilant sound, you need to bring your tongue close to the roof of your mouth and let the air flow out through a narrow space. This creates a hissing sound that makes it easy to hear and understand the word.
For example, when you say the word "snake," you can feel your tongue touching the roof of your mouth and the air escaping through a small opening between your tongue and teeth. This creates a sibilant sound that lets us know that you're talking about a snake.
Sometimes people use sibilants to make a hissing sound on purpose, like when they want to scare someone or pretend to be a snake. Other times, it's just a normal part of speaking. But either way, sibilants are an important part of language and communication.