studying = one way to learn

Let’s start by looking at the definitions:

To Learn – to gain knowledge or skill by studying, practicing, being taught, or experiencing something.

To Study – to read, memorize facts, attend school, etc., in order to learn about a subject.

Therefore studying is one way to learn. This is why we can say “I studied but I didn’t learn anything”.

What is the difference between learn and study? | ABA English