To enter into a computer the information required to begin a session.
進(jìn)入，注冊，登錄：往計(jì)算機(jī)內(nèi)輸入開始一個程序的信息
To enter into a computer the command to end a session.
退出，注銷：往計(jì)算機(jī)內(nèi)輸入結(jié)束一個程序的信息
(informal)very easy
(非正式)易如反掌
go through the procedures to begin use of a computer system, which includes establishing the identity of the user
進(jìn)入（系統(tǒng)），注冊，登錄
go through the procedures to conclude use of a computer system
退出（系統(tǒng)），注銷