What
In short
What is an interrogative pronoun used to ask for specific information about an object, idea, or action.
In plain words
It is a word used to start a question when you do not know the answer. It helps you find out which thing or which action someone is talking about.
A simple example
If you see a mysterious box on your desk, you might ask, 'What is inside this?'
Why it matters
Without these words, we could not seek information or clarify details in conversation. They are essential tools for learning and gathering facts.
Easy to mix up
It is often confused with 'which', which is used when choosing between a limited set of options.