When your pc connect to mosem with lan wire you have authority to connect internet .its mean power But when disconnect lan wire ,your pc has not authority to connect internet. But permission, when you have two user on your windows in pc , with different password When you haven't user password that mean you dont have permission to log in to that windows. I hope this be helpfull

For example: The doorkeeper has the authority to give you a permission to enter?

When we talk about right of access of computer or website, which word shall we use? authority or permission? When we talk about THE [OR a person's OR one's] right of access TO A computer or A website, which word SHOULD we use?

'Authority' is a general permission depending on your role and status in an organisation, for example, the company for which you work ; 'permission' refers to a particular activity, meaning that you have the consent [agreement] of the person who supervises your work or activity.