a means of entering, leaving, or approaching something, particularly a place

the right or opportunity to enter a place or see someone

the act of approaching or entering

(computer science) the operation of reading or writing stored information

a code (a series of characters or digits) that must be entered in some way (typed or dialed or spoken) to get the use of something (a telephone line or a computer or a local area network etc.)

to be able to use the information from a computer system, network, database, etc.