Intermediate 
The vice-president of Google has warned that piles of digitized material  blogs, tweets, pictures, videos and official documents such as court rulings and emails  could be lost forever because the programs we need to view them will become defunct. Our first steps into the digital world could be lost to future historians, Vint Cerf told the American Association for the Advancement of Sciences annual meeting. He warned that we faced a forgotten generation or even a forgotten century because of what he called bit rot, where old computer files become useless junk.
Cerf says we need to develop digital methods to preserve old software and hardware so that out-of-date files can be recovered even if they are really old. When you think about the quantity of documentation from our daily lives that is captured in digital form, like our interactions by email, peoples tweets and all of the world wide web, its clear that we could lose an awful lot of our history, he said. We dont want our digital lives to fade away. If we want to preserve them, we need to make sure that the digital objects we create today can still be viewed far into the future, he added.
What is bit rot and is Vint Cerf right to be worried? Accessing digital content in the future could be less of a problem than Cerf thinks. His warning highlights an irony at the heart of modern technology, where music, photos, letters and other documents are digitized in order to ensure their long-term survival. But, while researchers are making progress in storing digital files for centuries, the programs and hardware needed to read the files are continually falling out of use.
We are throwing all of our data into what could become an information black hole without realizing it. We digitize things because we think we will preserve them. But what we dont understand is that, unless we take other steps, those digital versions may not be any better, and may even be worse, than the artefacts that we digitized, Cerf says. If there are photos you really care about, print them out.