They are related in that they share the same base word, which is Interest. They are also both adjectives.
However, they are different in how they are used.
Interested is used to describe someone’s feelings.
For example, I am interested in your question.
Interesting is used to describe how someone perceives something external from themselves.
For example, your question is interesting.
Back in my teaching days, I let my students in on a simple trick to remember the difference:
-ING FOR THE THING