When you launch an instance, you should specify the name of the key pair you plan to use to connect to the instance. When you connect to the instance, you must specify the private key that corresponds to the key pair you specified when you launched the instance. Refer http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html
Add Key Pair using Zone (Region) and Key Pair Name.
Generate creates the Key Pair.
Key Pairs can be Deleted as well.