To store data in memory (RAM) or on a storage medium, such as a hard drive, SSD or flash drive. Writing is the same as recording. Every write operation in the computer implies a copy operation. For example, to write a file to storage requires reading the data from memory; thus, a copy of the data is made. See
read,
read/write and
storage vs. memory.
They Do Write Funny!
The zero/one, spot/no spot, charge/no charge, pulse/no pulse architecture has been the basis of digital computing for more than 80 years. In the late 1930s, a handful of technology geniuses determined that it was better to turn all data into a two-part code. After that discovery, all digital systems became much easier to develop. Make the spot or cell smaller and make the pulse shorter. Everything took off from that concept.