Computer data is essentially just information that can be processed, stored and saved digitally.

In its basic form data is simply a series of 0s and 1s, known as binary data. All data, including text files, photos, videos and audio files are stored as binary code. The smallest unit of data is a bit, or binary digit, the aforementioned 0 or 1. A byte is 8 bits long, and a kilobyte (KB) is 1024 bytes, not 1000 as you might expect; this is due to computers using the binary system as opposed to decimal. These days, files are rarely measured in KB, with megabytes (MB) being the smallest unit used. 1 MB is 1024 KB, 1 GB is 1,024 MB, and 1 TB is 1024 GB.

All data on storage media, including hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives and SD cards store data as bytes, albeit in different ways. As an example, if we take the Complete Works of Shakespeare – around 1250 pages – would be around 5,600,000 bytes, or around 5.6MB. In a photograph, every bit represents the colour, location, brightness, contrast, etc, of each individual pixel.