EC2 Instance cannot be accessed publicly

I have configured EC2 instance(Ubuntu 14.04) on AWS. Intalled JDK, Tomcat,MySQL to deploy my web-application. After deploying, I can access it using localhost or Public IP(Provided by AWS) from UBUNUTU (inside the ubuntu) but can not access from outside. I want to access it publicly. How to do that?

via Chebli Mohamed