Recently I wrote a blog post about my internship at a startup in Egypt ( http://blog.mbassem.com/2015/02/04/my-journey-with-trustious/ ) that helped me find my passion. I knew the kind of work I love but I can't find a suitable title for it. I think it's either an infrastructure engineer or a devops engineer. So I would love to know the difference between both of them from the requirements and responsibilities point of view. Thank you.
DevOps was originally supposed to be about moving dev and ops out of their respective silos and into one combined team so as to break down communication barriers and help each side understand their duties better. Under this model there is no such thing as a "DevOps engineer" as "DevOps" is a team structure not a job title.
Now days "DevOps" often just means "cloud deployment engineer" or "we can get a developer to look after the servers".
What you seem interested in is the ops side of things. Usually this will be under a title like sysadmin, deployment engineer, "DevOps".
Generally speaking there is little standard terminology for job titles. What is called "Infrastructure Engineer" at company A may be called "DevOps engineer" at company B, and "Deployment Ninja" at company C. When looking for a job your best bet is probably to search for specific skills, not job titles.
Personally I would call what you are interested in DevOps (I only skimmed the blog post). To me an infrastructure engineer sounds like someone designing and implementing the infrastructure of a distributed backend system, not someone dealing with deployment.
Now days "DevOps" often just means "cloud deployment engineer" or "we can get a developer to look after the servers".
What you seem interested in is the ops side of things. Usually this will be under a title like sysadmin, deployment engineer, "DevOps".