Personal data is information that describes who you are or things about you. It's information that can be used to identify you, like your name, where you live, phone number, email address, or even your age, weight, or height.
When you give someone your personal data, it's like giving them a picture of yourself. If you don't know the person or you don't trust them, you might not want to give them your picture. The same is true for your personal data.
It's important to be careful with your personal data and only share it with people you trust or who need to know it. For example, your parents or teacher might need to know your age and address so they can help you with things like school or medical forms.
Companies also collect personal data from you so they can provide you with services or products, like when you create an account on a website or buy something online. But you should be careful and read the privacy policy to understand how your data will be used, and always make sure the website or company is reputable and safe.
In sum, personal data is information about you that can be used to identify you, and it's important to be careful with it and only share it with people you trust.