log · noun C /lɔːg/
log
C1 a thick piece of tree trunk or branch, especially one cut for burning on a fire
Dictionary example:
Let's put another log on the fire.
Learner example:
People used to cook with fire logs [but] they don't do it any more. (Certificate in Advanced English; C1; Spanish)
log · verb /lɔːg/
log on/in
B2 to start using a computer or to connect a computer to a system of computers by typing a password and sometimes your name
Dictionary example:
I tried to log on as usual but nothing happened.
Learner example:
Well you need a computer and you have to log on [to] the Internet. (First Certificate in English; B2; Dutch)
log off/out
B2 to stop using a computer or program or to stop a computer being connected to a computer system
Dictionary example:
We were all asked to log off while some changes were made to the system.
Learner example:
I know that most students just log off the computers, but they [are] still switch[ed] on and [use] energy. (Skills for Life (Level 1); B2; Polish)