Related means connected to something else in some way. When two things are related, they share a link or association that ties them together.

Family members are related by blood or marriage: your cousins are related to you because you share grandparents. But the word reaches far beyond family trees. In science class, you might learn that sharks and rays are related species because they evolved from a common ancestor. When your teacher says that multiplication and division are related operations, she means they work together as opposites: one undoes what the other does.

Sometimes things are related by topic or theme. If you're writing a report about volcanoes, you'd include information related to how they form, where they're found, and famous eruptions. You'd skip details about dinosaurs or baseball because those subjects aren't related to your topic.

The strength of the connection matters. Shoe size and height are closely related because taller people tend to have bigger feet. But shoe size and board game skill are almost completely unrelated (other than the fact that older kids have bigger shoes and are usually better at playing board games).

People also use related casually to mean similar or comparable: “Your idea is related to mine, but different in an important way.” Understanding how things relate to each other helps you see patterns, make connections, and think more clearly about the world.