Data are the bedrock of science. Without them, scientific theories, which are nuggets of our understanding of how the world works, would have no foundation. Scientists see trends in data, which can help them formulate and later confirm their hypothesis.
Data is/data are
The correct usage is data are…data is plural; datum is the singular. However, many people use data as though it were singular – and this may be more true of big data or open data than data alone! Here, aside from this page, we use data as though it were singular.
The basic building blocks of computer data are bits. One bit can be one value, 0 or 1. This is pretty basic, so the fundamental addressable unit of data in a computer is more commonly the byte – a string of eight bits – which is enough to describe a single character of text.
Because of the binary counting system used in computers, successive magnitudes of data are not quite equal to their decimal counterparts, a discrepancy that increases the larger you go. Like this:
1 kilobyte (kB) = 1024 bytes (rather than 1000 bytes; 2% difference)
1 megabyte (MB) = 1,048,576 bytes (rather than 1,000,000; 5% difference)
1 gigabyte (GB) = 1,073,741,824 bytes (not a billion; 1,000,000,000; 7% difference)
1 terabyte (TB) = 1,099,511,627,776 bytes (not a trillion; 10% difference
1 petabyte (PB) = 1,125,899,906,842,624 bytes (not a quadrillion; 13% difference)
1 exabyte (EB) = 1,152,921,504,606,846,976 bytes (not a quintillion; 15% difference)
Big Data, Open Data