Deleting data is the process of removing entire or substantial parts of a data set.
Deleting data is handled different across systems, but common to all systems is that if you are deleting data you should be aware of the option to recover the data, as this might threaten your security.
Often when files are deleted from physical storage, only a pointer to the data is removed, meaning that the system “forgets” about data, but the data themselves are still there.