DVD STORAGE:
One of the biggest challenging aspects of data storage is long-term archival. All forms of data storage have a limited lifespan, and complex storage mechanisms, such as HDDs. One of the profit of optical storage, such as CD, DVD, and Blu-Ray’s, is their shortage of moving parts and relatively long life time of up to 100 years. The problem has always been capacity, optical storage has reached a declension of returns in terms of data stored due to the limitations of light itself.
In Australia, A team of engineers at Swinburne University of Technology have conquered that challenge by enabling storage up to 1,000 Terabytes of data, or 40,000 HD movies, onto a single DVD. They developed the process which uses a secondary laser to refine the refraction limit of light, which is around 500 nanometers. Since light cannot shrink below that limit, the ongoing technology cannot write information smaller than 500 nanometers. The Australian researchers employed two 500nm lasers. One actually writes data, and the other blocks the light beam, except for a sliver that is only 9 nanometers in length.
Jampack 1,000 TB of data onto a single disk has its challenges, but if coupled with new technology that extends the lifetime of a DVD (to 3x10E20 years), data storage can become nearly innumerable. Even at temperatures as high as 189 C (372 F), another new type of DVD being developed at the University of Southampton in the UK is expected to last 13.8 billion years, which is nearly as long as the universe has existed. Of course, all of this seems unreal and not destined for any real applications, but companies such as Facebook are already using innovative new storage arrays consisting of 1000 Blu-Ray discs to store up to a Petabyte of information at a time. The question is, do we really want our Facebook pictures to be around for 13.8 billion years?

CLOUD STORAGE:
Cloud storage is a service model in which data is maintained, managed and backed up remotely and made available to users over a network (Typically the Internet).
Cloud storage sounds like it has something to do with weather fronts and storm systems, it really refers to saving data to an off-site storage system maintained by a third party. Instead of storing information to your computer’s hard drive or other local storage device, you save it to a remote database. The Internet provides the connection between your computer and the database.
On the surface, cloud storage has several advantages over traditional data storage. For example, if you store your data on a cloud storage system, you’ll be able to get to that data from any location that has Internet access. You wouldn’t need to carry around a physical storage device or use the same computer to save and retrieve your information. With the right storage system, you could even allow other people to access the data, turning a personal project into a collaborative effort.
Features of cloud storage is Secure and Safe, Competitive and Flexible pricing, Object storage with a fully-featured API, Flexible access.¬
Disadvantages of Cloud Storage is Technical Problems, Security Breach, Speed Issue.