When you are "bored" it means that you don't have anything fun or interesting to do. You're not having fun. You might get bored when:
- you're talking to someone who's not very interesting
- you're working on some work that you've already done many times before
- you're waiting in the waiting room at a doctor's office for a long time
When someone says that they "are bored" they are complaining.
A: Mom, I'm bored.
B: Stop complaining!