Hardware & Networking

Hi Srinivas,
Mentioned all three are in a good demand in their own field but the common factor is Skill, Expertise and Experience to be considered to become a successful professional.
Now, if I will about the overall situation then DevOps will be the future but here to answer your question precisely the availability of DBA professional either Oracle and SQL is less than other two. Also, if you begin your career in DBA then, later on, you may move to Big Data, Business Intelligence as a career.
Whereas, you will find a good competition in Networking because a number of candidates are more.
Development has many branches and you need to decide which path you need to follow. As per current market trends as well as in future demand Java, Angular Js, Node Js, Python, Jquery and Apex would help you a lot in Cloud computing back-end programming and IoT.

Cyber crimes are the major threat to business enterprises and government entities. As per KPMG report most of the top 500 business enterprises have reported Information security breach in year 2015. There are two types of Cyber security experts Computing resources Cyber Security experts and Information Security Analysts. Computer Resources Security experts maintain computer and network security and update security programs as necessary. Information security analysts develop an organization's computer security standards; install software programs to protect information stored on computers, and monitor computer networks for security breaches.
Ethical hackers are specialised Cyber Security experts who work for all organizations which have an internet presence and use extensive use of web technologies for Business . Ethical Hackers role is a proactive one as they prevent cyber- crimes and protect cyber space from intrusion. They ensure data security and protect computer systems from illegal hacking activities. Computer Hackers use their expertise in computing and knowledge of programming, web applications, operating systems, assembly language, internet security systems etc. to protect computer systems from illegal hackers.
It is a niche skill and has limited career opportunities. However, if you able to break into your first job then its is very high paying and respected job. Most of computer hackers have graduation degrees such as B.Tech CSE/IT, BCA-MCA, B.Sc CS. Most of the hackers are those who have excellent programming skills.
You can appear in professional certification examination to become a Certified Ethical Hacker (CEH) by appearing in examination conducted by ED-Council. Certification is achieved by taking the CEH examination after having either attended training at an Accredited Training Center (ATC) or completed through self-study. CEH is a skilled professional who understands and knows how to look for weaknesses and vulnerabilities in target systems and uses the same knowledge and tools as a malicious hacker, but in a lawful and legitimate manner to assess the security posture of a target system(s). The CEH credential certifies individuals in the specific network security discipline of Ethical Hacking from a vendor-neutral perspective.