Good question! Human height (how tall we are) is something that is different between men and women, just like how their voices sound (men have deeper voices) and how our bodies are shaped (men and women have different private parts).

Height is controlled by hormones: chemicals that occur naturally in our bodies based on our genes.

Genes are like a recipe for making things in our bodies, and all living things (not just humans) have them - genes tell someone’s body, “Make this hair brown! Make these arms long!” Make this person tall!”.

Men and women have genes that tell their bodies to make different hormones - this means that men have hormones in their bodies to make to make them tall, while women have less of that hormone. However, it’s also important to remember that there are things that make us men and women that aren’t height - there are also very tall women and very short men. There are people who aren’t men, or women, or switch between the two. All of these ways of being human are valid, and they all result in very different heights!

Source: Chromosomal Sex Determination in Mammals