1. The reading or writing of data, with the connotation that the content of the reading or writing is taken into account. The word is most commonly used in connection with filed information and is often qualified by an indication as to the types of access that are to be permitted. For example, read-only access means that the contents of the file may be read but not altered or erased.

2. The right or opportunity to read or write data or programs. The UK Computer Misuse Act 1990 states that ‘a person secures access to any program or data held in a computer if by causing a computer to perform any function he alters or erases the program or data, copies or moves it to any storage medium other than that in which it is held or to a different location in the storage medium in which it is held, uses it or has it output from the computer in which it is held (whether by having it displayed or in any other manner)’.

3. To gain entry to data, a computer system, etc. In the US, to access strictly means to instruct, communicate with, store data in, retrieve data from, or otherwise obtain the ability to use the resources of a computer or any part thereof.