Copy-on-write

Copy-on-write (COW) is a means of optimisation in Computer Science. When several callers ask for the same resource, they can all be given a pointer to the same address. Only when they try to change the resource does a local copy need to be made. This happens without the caller noticing. It is done so that all the other callers do not see the change they did not do.

This short article about technology can be made longer. You can help Wikipedia by adding to it.