definition Computer proficiency ?

Computer Proficiency is a very broad term, and ultimately depends on what the user wants to do. For example, if you only want to use the internet to browse youtube and write email, then your level of proficiency is suffient if you possess some basic skills such as knowing which icon to click for your browser, how to navigate to the site you are looking for, how to turn volume up and down, one finger typing, and perhaps how to attach a file to an email. In the case of the user who only wants to do this basic functionality then they are proficient to their level...

The actual question you need to ask is what level of computer proficiency is necessary to perform a certain task - for example if you are a developer you will need to have a wealth of knowledge to perform a job. This will include coding, knowledge about hardware, operating systems, development tools, user experience, software specifications, computer networking etc, the list could go on. 

To answer your question 'define computer proficiency' - the definition is such - 'the user is proficient to the level of the task they are able to achieve' - proficiency is not ever complete, it is an on going process. I have been using computers and the internet since, and I still learn new things every day, I am proficient enough to write web applications, use computer aided design tools, set up complex networking and repair hardware, however I would not say I am proficient in generative AI training.